To the most illustrious Royal Academy of Scientists of Berlin

JOHANN GOTTLOBB LEIDENFROST

M.D. and P.P. University Duisburg

A Tract About Some Qualities of Common Water.

Duisburg on Rhine

At the Expense of Herman Ovenius, Universal Booksellers, 1756.

A Tract About Some Qualities of Common Water

Johann Gottlobb Leidenfrost

Here translated into English for the first time

By Carolyn S.E. Wares from the 1756 Latin edition

Published at Duisburg on the Rhine by

Herman Ovenius.

To the most illustrious Royal Academy of Scientists of Berlin.

John. G. Leidenfrost offers his reverence and wishes you health.

Your academy of scientists is something like the sea, which while it is fed by the Rhine and the Elbe and the great Oder, also opens its shore to many smaller rivers and does not deny admittance to tiny streams on its surface. Wherefore this little stream contains an observation of physics for you, not to add to your store of knowledge, most illustrious and learned men, but so that if it is in some way worthy it might obtain your encouragement and because it was not fitting to do it in any other way. For all of this pertains more to that than to your Academy under whose guidance we live in happiness. The work is undertaken to augment and enlarge knowledge, since from these lands some fruit has been received, which many distinguished labours you immortalize for gain and glory. And if those I can now offer are not great or many, your own magnificence will be the defence of my own insignificance and will justify my conceit. Therefore, I offer these observations which have been concealed for quite a long time until I might be more certain of their deathless and sure success. There is nothing which assists natural teaching more than certainty and constancy of phaenomena, since nature herself so conserves the same rules in all things. The force of it acts at a minimum, even as it rules with a maximum. Thus we are led to firm knowledge neither by a great mass or richness or display but only by truth of enquiry. When therefore I dared to draw certain conclusions from the evidence of water phenomena, I did it with caution and almost with fear. The doubt provided which I added will declare openly, as much as it can, that I joined to my thoughts the Euclidean rule, always secure, always unacquainted with error. For I know how prone man is to make judgments and how easily some false thought might persuade us. In withstanding the examination of a more severe judge a discrepancy is seized upon. And so, therefore, I decided to write primarily about water, but also about other common things, such as the lightness of fire in the centre of the earth in an absolute respect, also to teach a little about the Newtonian theory of colours, the opportunity of writing being brought forth. I have not hesitated to refute those opinions although I feel that nothing ought to be more terrible to me than that this presumption might be displeasing, to strive against such great and meritorious men. Perhaps especially I fear not a few condemnations because I attack the thesis generally established by that great man Isaac Newton, accepted universally by physicists, I know; and contrary to his opinion chemical experiments are to be demonstrated that not all thin layers of bodies are coloured, but only the oily ones, or those in which there is some phlogiston. And so, therefore, these objections are not born from impudence, but because I doubted the real causes. I hope they will pass equal judgments. So I shall write so that they will see the veneration which I offer to those great men and not deprive me of the freedom to esteem lesser ones.

You, therefore, most illustrious and learned men, if I dedicate these sparse pages to you, receive them with benevolence. Inflame and excite zeal in me so that having something better, I will succeed, having in mind the assurances of my betters.

I pray to God that he might wish the king health, and allow him to be enjoyed by the world for a long time with his incomparable donation. And God save your most splendid Academy for the good of the country, and in kindness liberally bestow benefits of life and health upon your fortunes. Written at Duisburg on Rhine, the sixth day before May, 1756.

A Tract Concerning Some Qualities of Common Water.

It is not my intention to set down commentaries about water or to repeat that which has been observed by our predecessors in this admirable body unless it is necessary to summarize, so they might be strengthened or amended through my observations. I shall write that which I have not read so far observed by others. If nevertheless those things have now been observed by others, I beg pardon for my ignorance so that they might surrender their readers (willingly). Nor do I fear on that account that my enquiries will be despised, because they are unimportant, obvious to anyone, born without great preparation, and easy in imitation. Truth holds a work neither in a bag nor under a cover. I was persuaded that no experiments in physics are better at the moment than those which are begun in the more simple bodies, such as common water. For often things in composition are so complicated that it is difficult to draw out any certain and faithful rules from them. For something may easily lie hidden in complicated things, because we may overlook things with which oversight the whole demonstration is useless. In more simple things error is more simple, and

easily extracted. Actually, whoever chooses to examine for himself the general rules of motion should also contemplate the design of animals, moved with very intricate motions. How difficult the way becomes and curved the path, distasteful because of its so many errors! Thus, whoever wishes to investigate the general qualities of material bodies (so far not enough observed) can not measure enough the simple phenomena obvious in the most simple bodies when these are put together outside of the others. Through themselves alone, or by such ones elsewhere, even in a quite simple body, they are moved changed, effected. Whoever has become acquainted with these phenomena is he who more securely plots his path. Not offended by many halts, he proceeds to the limit when he works in well ordered things. The wise man seems to move the admiration rather than to truly benefit the sciences.

Moreover, no life can be begun or continued in these lands without water. No matter who may seek a contrary example, he is frustrated. And Plutarch of Chaeronea says, as he shows in an elegant investigation, that water as well as fire exhibits its use to men. He says that alibantas ? are called dead because they alone are freed from all liquid and

humidity. The reason for this is that all mankind seems eager for knowledge of water. For in finding, separating, collecting and dispensing it a great part of the public as well as private economy is occupied. The theologians have a very important object in water . Hardly any other search is more important and illustrious than concerning water, in natural as well as civic opinion.

Mathematics has tried to measure the motion, force and equilibrium of water in statics and hydrostatics. And before the end of the measurement it finds itself wearied by this different and difficult thing. Who can count in how many volumes about medicine all the medical authors who wrote enthusiastically about the use and abuse of simple and mixed water? Physics explains about the origin, the causes and the effects of water with much strength and excellence – in respect to those changes, at least, about which one can or ought to speak. Chemistry, since Physics outlines its special part (which proceeds from the material beginnings of bodies), examines the substance alone and when mixed, with the consideration of the motion of the whole structure or the motion of progress. The chemist says he also teaches a little about the matter, generation, composition, change and corruption of water, and of these few with not enough certainty. For little is catalogued from all of these simple assertions about simple water which are treated as truths in physics and chemistry. I am trying to augment this catalogue with one or another assertion. I will not dispense these reckonings except thriftily for this reason. And those which are uncertain I will always derive from certain ones. Perhaps nevertheless, sometimes, if besides one method there is a certain other somewhat related, I will approach the thing less pertaining to appearance, because I rely upon the obliged reader of the following matter about to be presented.

III

Without doubt, all antiquity saw water to be a fluid, a vapour, something cold, something with some heat, fever, ebullience, in which changed vapours were made volatile. The same increases some in ice, dissolves certain salts, abandons solid earth, and is repelled strongly by fats. Similar phenomena to these most true ones are very common. So, in truth, these only contact the senses. Nor can they acquire or benefit or aid understanding unless in separate, single phenomena. And due to the reason of circumstances following the law of fixations certain measures are sought. Thus it is certain that in this question I propose to include nothing unless very little from former authors concerning physical things nor the hypotheses from the lacking lips of all men.

The simplicity of water is said to be the first thing observed about it by a philosopher. So, I will say no more about Thales of Milesia, who explained more from ingenuity than from observation that water as a single principle is the element of all bodies. Nor will I discuss the Democritan school, which in this business of elements asserts with no greater faith that fire alone must be joined with water. It is clear that great Aristotle, who was seen to have demonstrated first to himself the necessity of the four elements, diligently

with thought out discussions and the observations and opinions of his ancestors, did not refuse a favourable place to water among the most simple bodies. And the Aristotelian hypothesis of four elements, although I might not wish to defend this for a truth, nevertheless is an elegant hypothesis so near to truth, so responsive to several phenomena that I wonder in what manner the more recent age of man can accustom itself mutually to this secret remainder and much more uncertain creation of physical elements. For it is necessary that all of physics has two hypotheses. First, that it is full of explanation from the posited principles of phenomena. Finally, that these principles may exist in reality.

Nor are they the entity of reason, predicted for the pleasure of fiction with the hidden qualities of all arrangements. Which pair being required, certainly it is allowed to say this in passing: neither in the three repeated principles of chemistry, nor in the three Cartesian notions are they found. For while I say nothing about monads, the doctrine of which pertains more to metaphysics than to the knowledge of natural bodies, the principles are filled with nearly nothing of the salt, sulphur and mercury of chemists actually, unless you use earth and water as principles reduced in that philosophy. Because salt is understood even in the most simple sense not to be plain, but made from both earth and water. And fire is a mixed body and for that reason it is seen to be glorified like the first element in vain. Truly the Cartesian triad talks wrongly about the twisting of particles, primarily because none can be shown to the sense, nor by any way of reality can there existence be shown. Rather by the luxury of notion it is arranged by chance. Finally, it happens so with them because the good aether labours with all phenomena to fulfill. It occurs in the affairs of the heathen god Jove, which troublesome events most agreeable Lucianus also charmingly derides in his two accusations and here and there elsewhere.

When, therefore, Aristotle claimed that the simplicity of water be selected, he does not wish (nevertheless) for it to be had from a certain origin and immutability. Rather, he believed in four elements, which he set forth in the order of the overthrown, and from these two joined with each other, from the vanishing form of the one the third ought always to be able to be born. He concludes the idea of motions from general laws and from the primary qualitative observations of bodies, as they say.

For Aristotle says throughout that he will not have these four elements through the prime material, but through primary and very simple modifications. See De generatione et corruptione. Granted – I might again not wish to make or defend my opinion about the axiom. I marvel nevertheless at the shrewd wise hypotheses, the beauty of which the present day is hardly aware, from which the Greek philosophy remains to be read. For he first supposed that the most perfect motion of all is circular and from the circular motion there followed to be no heavy bodies, no light ones. That coincides enough with a certain teaching of those great men Huygens and Newton – a curvilinear motion if (as you wish) in both of the two: one revolving centripetally, the other centrifugally. It strives

from the centre or middle. He supposes secondly the condition of nature by which bodies are thus dispersed in these two motions. Some bodies are always heavy, i.e., earth; some always light, i.e., fire. Of, if, because of the same thing, bodies attract themselves, certain ones always flee themselves. And primarily for the reason that certain bodies always strive to the centre of the earth, certain ones always try to draw away from it. All more recent physics considers to what extent the matter of the body in which it occurs might be shown through chemical experiments, and in turn, this about particular motions: in what manner they attract themselves, again how they flee themselves. Such about the pure earth is most certain, that as long as the earth is solid and not conveyed beneath with other bodies, it is always fixed, that is, always heavy. Always it strives towards the centre of the earth, so chemical experiments above all turn out. However, fire is pure and

does not adhere in other heavy bodies as if in prison, always volatile that is, light and

centrifugal, not drawn to the centre of the earth. Even if Boyle denies it in his book on the ponderability of flame. This book nevertheless does not distinguish between pure fire and the composition of flame. Nor did it regard the weight for airy bodies insinuated with fire. However Herman Boerhaave in the work of an immortal chemist restores the absolute lightness of pure fire with greatly similar arguments.*

* Obviously, Boerhaave teaches that a great enough mass of iron or copper greatly heated through fire, weighed on two scales, is not a bit more heavy than the same mass returning slowly to coolness. He describes an experiment made by himself on a parallelepiped of five and a half pounds of iron, and also a similar mass of copper. I know that several erudite men, especially the illustrious Musschenbroek (Princ. Phys. & 787) have opposed the conclusions which B. Boerhave prepares from these experiences. This is because of hydrostatic reasons, since molten iron clearly occupies a greater mass than when cooled, although it is specifically lighter. The greater part experiences support from the air in which it is weighed. Hydrostatics take these reasons into account. But the weight of the present fiery parts cannot be known through this experiment because the iron acquires greater weight from the fire than does the air because of the greater mass of the iron; moreover, for these same reasons the heated iron ought to be even lighter, and to rise on the scales unless it is pressed down by the weight of the acquired fire. I must disagree, in this difficult matter, with the calculations of the distinguished Musschenbroek nevertheless noting the reverence due to such a meritorious man.

Without contradicting the unswerving desire of acquiring truth, I must warn that when, in this computation, mathematical method is applied, all that immediately disappears. For as assuming the data which that illustrious man assumes or which he certainly does not dispute:

I. A cubic finger of rain water equals 311 grains (Musschenbroek loc. cit., & 704). The specific gravity of such water is to the specific gravity of iron as 1000 to 7645 (same place & 703). When 1000:7645 = 311:2377 595/1000 = fingers. That is one cubic finger of iron weighs 2377 grains. Therefore the weight of the iron mass weighed by Boerhaave was 5 pounds and 8/12 (or 8 ounces), or 88 ounces, that is 42,240 grains. Then the mass

of it was 2377:42,240 = 1:17 1931/2377, that is the Boerhaavian mass of iron occupied 17 1931/2377 cubic fingers in a cool place.

II. Therefore when we investigate the enlarged mass of this parallelepiped that occupies 17 1931/2377 cubic fingers in a cool place, it is important to know what fractions have been conveniently omitted in the calculations. White hot iron is expanded through 1/60 of its own length (Boerhaave Chym. P243 f.) . So, for example if 17 cubic fingers in a cool place (errors taken out) equals a³ , the same mass in a heated place, will be, for example, expanded in three dimensions through 1/60 of its own length equal to (a+a/60)³= a³ + 3a³/60 + 3a³/3600 + a³/216000 = 17 + 51/60 + 51/3600 + 17/216000, it is plain that this is less than the Boerhaavian mass of heated iron of 18 equal cubic fingers.

III. Consequently the entire increased mass did not make one cubic finger in the Boerhaavian mass of iron. And also not even one finger of air is displaced by this

expansion, so the support given by the air to the heated iron is less than that of 1 finger of air. Now the weight

of one finger of air of medium warmth equals ¼ grain. By which means the resistance of the air against the Boerhaavian heated iron was increased by less than ¼ grain, which, because it is of so little weight, can not be detected on the scales, from which the several pounds hang.

IV. It is truly undetectable because the atmosphere of the air in that place where the burning iron is, is rarefied to the point of a vacuum. Thus it offers little support. Nor is this changed because the hotter air decreases in weight and acquire greater elasticity, and, with this elasticity, can better support. For this elasticity that is present in such heat emitted from the white-hot iron in fiery rays does not support the weight of the iron. Moreover it is questionable whether the elastic air is really so hot.

V. Therefore it follows from this demonstration (see III), that the weight of fiery parts in Boerhaavian iron, if it was sensible, is not sensible beyond 1/ 4 grain. And from the demonstration (see IV) it follows that the sensible weight of it was nothing.

VI. However through Boyle’s observations, the increases of calxes and metals hung near a fire, and through those which were repeated in the Academie Royale Parisien and those which most illustrious Musschenbroek added to (same place following) the weight of fire, insinuated and fixed in white hot metallic bodies ought to enlarge and give a great increase in those weighty bodies. By which means if part of the fixed fiery matter gave a great weight, the weight of the much larger matter ought to be observed, if truly fire is heavy.

VII. There are those who think this controversy to be of small moment, and has little to add concerning physical things, but they do not notice that the absolute levity of fire could be demonstrated. Also universally a theorem may be a false physical example, namely that: the weights of specific masses and the masses of bodies with specific weights are proportional. For heated iron has more mass than cool iron, nevertheless it does not have more of specific gravity. For the rule cited a

little before this, assuredly is not completely valid in chemical experiments, particularly in some cases and especially in effervescent solutions. The applicability of common hydrostatic laws to the specific gravity of bodies, merits study concerning its serious limitations.

VIII. So therefore concerning fire, whatever fire is, I am certain that it is not changed into other kinds of bodies. But I have devised another experiment to determine truly whether it is heavy or light. In fact it seems to me that this quarrel can be settled by this method. If we can but ask what other force diverted by the force of gravity (for example, a horizontal projection through some spring in a heated body, and in the same not heated it impresses equal motion, and equal effect from that motion is produced in each case. For when we intend to explore the weight of fire through its gravity, some excuse always remains but in truth the weight it supports is so little and small that it escapes our senses. In this view I had a strong spring to be made for me 2 ½ feet long, from good steel, which on one end was shaped into the form of a shell, in which I could place an iron globe. On the other end of the spring were iron hooks firmly fixed on the wooden wall, so that if the spring was stretched, it was parallel in this way to the wall, and perpendicular to the horizon. If, in truth, that spring returns itself,

stretching with a resolute force, it will recede from the wall in the lower part, and the iron globe placed on the lower end will project by itself through a horizontal line, which globe finally through

a parabolic line tends to the earth. With this instrument completed, so that I may obtain use from it, I reason thus:

(a) Equal force produces equal motion, through which from the same spring stretched in that same position, the same iron globe, if all is rightly set up, through equal space, and through equal time is always projected.

(b) If therefore from the same and equal force, truly on that same spring diverse bodies of the same magnitude but which have not the same mass, for example iron globes and wooden globes, are projected, what then is the greater swiftness in the body? The one which has truly the less mass in the globe ( for example, in a wooden one) and the lesser swiftness in the body which has the greater mass, as in the iron globe.

(c) Because therefore the speed is determined through the space divided into time, it follows that in these two globes, if the times can be put equal, the speeds will be proportional to the spaces, so that (see (b)) the spaces are reciprocally as the masses.

(d) If I suppose fire to be a body, nor still to gravitate toward the centre of the earth, but by the reason of the earth to be an absolutely light body, then in following that the iron globe heated is not heavier than the same unheated, and still in the heated globe there is more mass than in a cool one, because fire entered into it.

(e) By which means from this hypothesis (d) if the heated iron globe and the same not heated fall from the same height (in a non-resisting medium), they approach the earth in the same amount of time.

(f) If either one is projected horizontally by the same force from the same height, each will describe a parabola, then by two forces it is urged, one projecting it horizontally, the other perpendicularly, in truth gravitating to the centre of the earth.

(g) And when weight in two things is supposed equal, they are divided one from the other in equal parabolas and in equal time, i. e. either globe approaches the surface of the earth in the same space of time, and that the first globe touched the surface of the earth, it quieted immediately (unless perhaps new motion must be produced by the repercussion). It follows in both globes, if they are equally heavy, in these circumstances equal times of motion.

(h) Then in truth in the heated globe in which is supposed the greater mass engrossed from the fire than in the same globe cooled (d) , the times of motion are equal (g) and the force projecting equally (a plus b) towards the horizon, it follows that the spaces are proportional to the masses reciprocally (c) ; and as far as the heated globe in a horizontal line because a greater mass travels through less space; in truth an iron globe not heated travels the same space in the same line better. By which reason the heated globe falls nearer into the mud from the point of projection, the same globe cold falls farther away. Also fewer semi-ordinates were in the parabolas which the heated globe described, than in those which the cold globe described, so to these same departures they are applied.

(i) And because (in a non-resisting medium) if the times are equal, and

the same projecting force, the spaces and masses are reciprocal (h plus c) it follows from the difference of the semi-ordinates that it is the same thing, from the distance of the points in which these globes hit the earth, from the wall from which they were projected,

that from the difference of semi-ordinates in these two parabolas one can know the difference of masses.

(k) So that these can be repeated rightly, it is necessary that all of the movements be in a non-resisting medium. For the heated ball, because the mass only increases in greatness, suffers the greatest resistance, when projected in the air than does the same one cold, which is of less mass and greatness. Therefore the heated globe not only because of its greater moving mass, but also because of its greater size, is resisted more, and moves a distance that is less than that moved by the cold one by the inverse ratio of its mass, and by the inverse ratio of increasing size.

(l) However, the resistance of the air for any body is as the ratio of surfaces. Also if we assume two globes with perfect sphericity they would resist the air by ratio of their squared diameters. Iron is known to be expanded by fire, as I have assumed through 1/60 of its length. For this reason if the diameter of the cold globe is made equal to 60, the diameter of the same globe heated will be equal to 61, the squared diameter of the cold one equals 3600, and in the heated one it equals 3721. For which reason the resistance of air against a cold iron globe, and the resistance of the same air against a heated iron globe, projected by the same force,

are in the proportion of 3600 to 3721. because of this air resistance the heated globe falls to the earth nearer to the line of projection than does the cold one, in the relation of 3600 to 3721. the semi-ordinates of the parabolas which each globe describes, if they are referred to equal starts, are to each other as 3600 to 3721 just from the resistance of the air.

(m) If therefore this is tried, with the spring apparatus described, and if the heated globe falls to the ground closer to the line of projection, then this distance is to the distance of the cold one as 3721 to 3600, then one must credit that additional distance not to

the air’s resistance, but more to the increase of mass from the inducted fire. For which reason the quantity of the mass of fire can be determined from this difference.

IX. This was my reasoning, before I tried the experiments. Finally after trying them with several changes, I performed the experiments in the same manner. I observed several proportions with variations depending on whether there was in general more or less quantity of fire in the globes, whether extending in that type of spring, or other circumstances. Nevertheless, always and constantly, if the spring had been stretched in the right way, the heated globe fell into the sand closer to the wall than the same one or an equal cold globe. For which reason through these former observations, it is established that a copious mass of fire hides in a heated iron globe and can be compared to a weight greater than a few grains, although

in all this heated mass no gravitation toward the centre of the earth is seen. I confess however to have used several globes, of diverse magnitudes, so that I might take experiments of diversity. I cease however to speak more about this because I reserve it for another occasion. However this is my method of determined whether fire through the reason of its mass is also heavy proportionally, this I want to make public, so that if something is changed in it, I can find out from learned men. Before I conclude I will set forth something from the experiments by this method.

Whence it stands without right and deeply unworthy that from the absolute lightness of these certain bodies, by the more recent the old philosophy is attacked. Aristotle

supposes in the third place, between earth and fire, two middle elements, water and air, since indifferently having weight and levity, so nevertheless as air for lightness or volatile

centrifugal, therefore water inclines more to a centripetal position; in which I suppose not many an author to have been deceived, very true it is, that about water no one contradicts, that it is something heavy, something very volatile. Thus also of air Mayovius and Hales assert the double state: now fixed, now volatile, who are excellent men to follow. The Stagirite supposes four primary motions, that is besides the heavy and the light, the four to be principles and cardinal qualities of elements, from which all sensible effects of the bodies remaining depend: namely, calorem (heat), cold, humidity, and

dryness. So if it pleases you to hear the whole thing expressed in today’s terms which bodies are elastic, which one non-elastic, which ones fluid, which ones firm. For on! With dishonor they explain Aristotle, and they show the peripatetic physics to be studied in his lectures, or interpreted or mocked, who under the term of calor (that sensible quality of a body with which our senses are affected with heat, and which heat is in our nerves only and not in the body) is with a warning. For they think understood by Aristotle caloris a force similar to congregation, and dissimilar to segregation; and in like manner cold is said by all without discrimination to congregate by itself. These two qualities I claim expressed today by apter terms of mutual attraction or flight of the particles. We understand all this theory under the very general word of elasticity. But

truly limitations do not now permit us to explain these and other things according to the true thought of Aristotle, and it suffices to indicate that Aristotle attributes a non-elastic and firm state to the earth, as essential attributes, or cold and dryness. In which I say that neither the errors of the philosopher nor the more recent experiments which physics and chemistry call to witness unite common opinion. Of the five elements Aristotle supposes, two have no common quality, to always to be able to be joined and to be mixed, thus so that as one form degrades the other, a certain new thing emerges; this contradicts neither reason nor experiment in any way. And from these five supposed premises the most ingenious author concludes that the changes in themselves are elements, and from the two joined always the third to be born, just as he asserts no less that all other bodies are composed from the four, and he further argued this in the best form of syllogism, from these premises. There are not possible more than four changes of elements, however innumerable the remaining bodies, also that four such very simple bodies are given, and innumerable mixed ones in whatever way it might be, his method following of testing the thing will be clear, which nevertheless ought to be explained at least by me. But I will only present those which concern water. He shows therefore that water is born if earth and air are intimately mixed. And water can be resolved into earth and air again. Clearly the earth, with its dry character, and air with its caloric character, if concreted form a cold and humid body, which qualities are suitable for water alone. In truth it is reasonable to join fire with water to generate air, or earth, for from water, with a humid character, and fire with a caloric character, earth is made. On the contrary, water with a cold character and fire with a dry character take form in air. For concerning those changes not pertaining to water, space does not permit me to comment.

VI.

This is that renowned argument of Aristotle by which he proposes to change water through fire into earth by force sometimes, and sometimes into air. In

10.

which nevertheless also when the argument is best, he is unable to quieten the extensive physical knowledge unless he attacks an experimental trial. Undoubtedly nature does not love celibacy, for it connects the soul of the body, thus it does not value alone the syllogisms of the mind. Which senses are not filled with evidence, nevertheless these notes are suitable, because this Aristotelian hypothesis, born from good reasoning, to this great day applied to the problems of physics, that can be so rightly resolved and demonstrated through experiment. He unites and renews all of the physical teachings, he knows, if we do not know, the principles of bodies in their conversions. Wherefore briefly we will consider those sensible ones about the nature of water, that, as the peripatetic hypothesis permits, either I correct or corroborate from them.

VII.

And because the first conversion of which Aristotle treats is that of water into air, it was probably always frequent. For water with warmth is dispersed into breath wholly like the air, very elastic, and with an impetus of particles fleeing from themselves to burst forth from the surrounding space, which antiquity saw in the ancient aeolipile. For from this they have explained the nature and origins of winds in philosophy, as Vitruvius teaches (Book1,chapter VI) where wind, he says, is flowing air with fluctuations of redundant motion. It is born when heat offends the dampness, and the impetus of heat expresses a force of fixed spirit. However to be sure it is allowed in aeolipilic air to look, and express truth from the wide thoughts of the air, by excellent artificial inventions. For the aeolipiles are made empty of air, they push in a very narrow point, in which the waters are poured and they are placed on the fire, and before they heat they do not take in any breath; however as they become heated, they show a strong wind to the fire.

Thus it is allowed to know and to judge from this very brief and small display about the great and immense sky of winds and the reasons of nature. From these same causes now Aristotle explained the winds and motion of the earth long ago. And Cartesius (De meteor, discourse IV) from the same exposition of winds and breathing thought to clarify matters. However the great Wolfius (Tent. phys. Part 1, & 174), observes the breath emitted from the aeolipile and with a glass dish turned over the form of moist vapor adheres to it, and slowly truly in little water drops forms again, at the bottom. The spirit of wine from a similar aeolipile with the breath rushing out does not change its nature, so that this breath might grow warm to this and to all notations truly is windy? With similar experiments on the spirit of wine erupting through the orifice of an aeolipile and producing a salty fountain of fire, which he took from Hamel (Histoire Academie Royale Parisienne, p.189), whence the great Wolfius concludes that in this experiment the Aristotelian transformation is in no way demonstrated. Nevertheless with the permission of the illustrious author I conclude from his experiment on the collection of vapor in watery drops no other result than that not all water enclosed in the aeolipile will be changed into air, but part of it in truth remains water. For the experience on the spirit of wine has some peculiarity, about which I will make a comment later on. In general therefore it is certain by reason of the aeolipile, that water of great heat is converted into a wind similar to air, as Wolfius concludes (loc. cit.) but as to how truly it is air must be studied by other experiments.

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VIII.

For in the said experiment now he urges caution because not until the last century was it known, from the remarkable large machines of Magdeburg, published by Otto Guericke, and from his emendation by Boyle and of others, that in this very simple water there is true air within certain spaces of the water, which either through heat, or through reduced pressure of the external atmosphere is expanded, forms bubbles, and produces a motion of bubbling in the water . For this air is neither produced nor generated from fire, but rather existed before being expelled in the manner above. For boiling is able to be made without fire, for placing water in the receiving vessel of the pneumatic pump it boils after the atmosphere is exhausted (see the learned Musschenbroek Elem. Phys . & 733, and others here and there). In truth the same abundance and portion is certain to lurk in many stages in water, when the mass of the same water is able to boil for a very long time on the fire, nor is not all freed into the air even when deeply cooked. In the degree of heat which boiling requires, a very obstinate remnant of air is seen, so that not unless gently and as if mixed that sense drops. Wherefore it is certain that water deprived from air thirsts for its own kind again, and if it is given free access to it, even from the atmosphere drinks to satiety. For water exhausted of its air by a pump, and quickly placed in upside down vessels, takes in a discharged air bubble, so that its mass divides or spreads out in the ratio as the quantity of the other liquid is diminished, from the first observation of de la Hire (Academie Royals Parisienns, 1711), which was more wisely and clearly repeated ( see distinguished Musschenbroek loc.cit. ).

This is certain that the expansion of water into breath possesses great forces and enjoys hardly measurable elasticity. As the vapor of small drops not only expels all existing air from a large glass or airy globe but a little after the globe can nearly entirely filled up with mercury. It can move also an immense weight, as the discovery of Papin (Act. Erud. Lips. 1690) and other teachers. For a calculation shows that drops of water, changed into wind, occupy a greater place by 14000 positions than before, and it can be extended even farther ( see worthy Musschenbroek loc. cit. 729) which despite this holding an enormous position can be easily cooled to the first mass. Whence it is clear that the vapor is elastic also, and in elasticity surpasses all known bodies. And perhaps it can show more, if a great deal of fire might be suitably allowed to be applied, as from that very brilliant observation that the illustrious Ellerus presents in his communication to the Academy Regna Berolinenci 1750. For he knows that when glassblowers form very large chemist’s vessels by blowing through an iron tube, the breath does not fail for such a mass of expansion. They are accustomed to replenish the mouth with water, and they blow it with the breath. For this water in such heat as of melted glass is converted into elastic vapors, nor does it return thereafter to the form of water.

This is all the more curious because water itself, for however long it remains in the form of water, is lacking in all elasticity. Also Aristotle nearly admits, while the frigidity of water or a non-elastic state just as some primary quality he ascribes. Water, he says, is by no means soft or compressible. In fact a great part of it moves with the least compression, but opposes around, from the opinion of book 4, chapter 4. But even with the very celebrated Florentine experiment, where it is plain a metal globe or

12.

press filled with water and beat with a hammer does not sustain the pressure. Rather, it transmits wet drops of water through very small pores of the metal, beyond all doubt. For because Boyle very cleverly does not complete the experiment, it proves nothing. After which Boerhaave shows the causes of error and bad results in the Boyle experiment, in Elem.Chem., the chapter about water.

XI.

However the incomparable chemist, George Ernest Stahl, is opposed to this non-elastic state of water, ascribing hardly some to water but also the greatest elasticity to the whole. So that among the ideas of Stahl here and there are recounted these elastic qualities of water (see Cel. Juncker, Consp. Chem., Table 1, page 33) Whence therefore under this title of elasticity another quality close to it is misunderstood, because water is expanded through fire into elastic vapors similar to air. I do not see in what manner these might be said to be discovered by Stahl, for they were known before from Vitruvius. On the contrary, most certainly it can be referred to antediluvian knowledge and exists in many books of physics laid out from accurate Italian and English observations. And also undoubtedly in a joined example in which B. Stahl speculates (see preceding) about the bombardment in a place loaded with ashes of fire with water, about the same action in the fire ashes from the water particles diverted in the presentations in native mineral alkali etcetera, nor others they show, unless water in an elastic state is able to be resolved. However, of that same water, as long as it retains the watery form, they prove the elasticity at a minimum. Unless, however, I think and venerate the wisdom of Stahl, as it might be sought with knowledge in such glory of popular discovery, and rather shall I believe another of that same possibility in the elasticity of water known to have been discovered, as not enough is laid out in writing.

A more distinguished and more wholesome thing for the whole of physics was the discovery of worthy Amonton’s Law (Academie Royale Parisienne 1702). It is obvious that simple and pure water boils at a determinate degree of heat, which neither is increased by the amount of fire applied or longer continued, nor diminished by decreased: the notion of boiling is continued. For we have in this degree some fixed measure of heat, for the rule of which the heat of whatever kind of body is permitted to be measured. For surely it can be said how much from this one observation the light will have been kindled not only in general physics in making thermometers and scales, but afterwards in the determination of the degree of heat, in which plants thrive and animals are spawned. Then in the theories of fermentation and effervescence, but also how distinct ideas will be born from medicine in diverse measurable degrees of heat of diseased human bodies. So that accordingly Herman Boerhaave wishes to have this observation because most full, which is enlarged and promises use, through one from the first ones of this generation. And neither must the Fahrenheit correction be thought to detract from the value of his experiment. Rather it is corroborated and conveyed to great evidence of certitude, from which marvelous Fahrenheit sums up an account of how the diversity of the atmosphere’s weight changes a little more or less the warmth of boiling water. For we easily define this variation of the law from the Barometer. Nor is it any contradiction that, through the machine of Papin, lead and tin in the midst of waves can become liquid. When we consider compressed air in Papinian jars is given great elasticity by the action of most of the overlying atmosphere.

13.

XIII.

Water exposed to heat vanishes and slowly is taken away; therefore it diminishes the mass through evaporating. For changed into elastic vapors, these light beings ascend to a higher atmosphere – whence clouds and fogs. But in what manner it does is disputed diligently by philosophers. Especially the secret quest by many beings is aroused more considerably on the origins of fountains and streams from vapors and rains. My goal forbids me from thoroughly noting that which has been thought about these things by very learned men. The Leibnitz hypothesis, namely, exhaled water is changed into less full bubbles with air hot, elastic, and expanded, and from the imprisoned lesser part of the air through heaviness above a heavier atmosphere these are elevated and float in this, for a long time has been predominant so that it is believed by nearly all men, although it is shown with convincing arguments not to be a sufficient hypothesis by explaining phenomena. Therefore they have tried to correct that. They substitute a certain aether spirit for air in these bubbles, and join to it the duty of driving water above the atmosphere, which thought the illustrious Eller favors, loc .cit . and very learned Kratzenstein. Cohesion of water particles with assisting air the brilliant Hamberger calls it and he holds that the whole thing not unhappily is explained by the solution theory. It is necessary for water to be loosed from air as salt from water. Others defend the propulsion only of water drops from the fire toward the upper regions. All of these hypotheses are seen to have something of truth, and no matter who puts forth extraordinary or despised experiments of these causes. Nevertheless, so that truth might be manifest, after which I read through the most recent from these writings, it was evident that not very many experiments have been tried on this matter, nor enough variety of them so that from them anything can be concluded with safety. For the exhalation of water in a space empty of air, which I see for the understanding of the best cause of motion is denied by none, affirmed by others, we ought not to doubt anymore that water has been evaporated into that empty space. Most recently the learned Krafft has examined the matter with extreme care. In jars of the same width but of unequal depth, more evaporated from the deeper than from the shallower with the same degree of heat, according to many observations said to have been made by Derham. However the excellent expert Khun denies this in the translation of On the origin of fountains, &103. it is certain that heated water evaporates less than cold in certain circumstances. As common experience teaches daily a strong heat benefits evaporation in dry linen and in condensed solutions. Wherefore the degree of evaporation is not seen to follow the law of heat degree, therefore that law ought to be determined more accurately through experiment.

XIV.

Another part of the Aristotelian hypothesis is that certain water is changed by fire into fixed earth. This was exploded a long time ago. And the incomparable Boyle recalled and advocated the experimental test (see tr. On the origin of forms Exp IX)), in which another similar experiment is reviewed by Borrichius (De Herm. Sap., C.), where also the very learned Edmund Dickinson is challenged. However the incomparable Herman Boerhaave boldly contradicts all these. Again, the learned Eller in the chronicles of the Acad. Royale Berolinsi confirmed the Boyle experiment although by another

14.

method. I know how Helmont solid parts of plants and growths were made from water alone and which and for what purpose Woodward responded, and many men after him, but I decline to lower myself to touch upon this quarrel. I will show that the fixation of water in fire for different degrees of fire is different, nor does its volatility increase or decrease in equal measure with the degrees of fire. And I hope that if nothing else, it is a peaceful, simple, and new experiment of truth.

ON THE FIXATION OF WATER IN DIVERSE FIRE
XV

1. An iron spoon of any size, well polished within and free from rust and dirt, is heated over glowing coals until it glows with light. To this glowing spoon, removed from the coals. send through a glass tube of suitable length, of which the other end finishes in a very narrow capillary canal, one drop of very pure distilled water. However the water which I have used was certainly as pure as can be made through distillation. It dissolved whole nitrous crystals of mercury without color, nor did mercury precipitate in any way, nor was it disturbed by alkalis. Moreover the water which I mostly used runs into a protected pool, now and for 6 and some odd years. No disturbance was noticed in all this time. Even with ordinary non-distilled water one is allowed to assume a nearly similar event. In any case such a tube as I have just described is right to use so that one drop always equal to another falls from the small opening, nor does varying in the magnitude of drops make a difference in the experiment. This drop which first fell upon the glowing iron is divided into a few little globes, which nevertheless after a little while are collected in one great globe again. At the instant when the drop touches the glowing iron, it is spherical. It does not adhere to the spoon, as water is accustomed to do, which touches colder iron. Nevertheless in the first moment of contact the glowing iron around the drop is black, indeed very black in a space which is greater, the brighter the iron, as if the matter of light and fire from the glowing iron suddenly was snatched into the water.

2. If then the spoon remains motionless, this water globule will lie quiet and without any visible motion, without any bubbling, very clear like a crystalline globe, always spherical, adhering nowhere to the spoon, but touching it in one point. However, although motion is not visible in the pure drop, nevertheless it delights in a very swift motion of turning, which is seen when a small colored speck, for example some black carbon, adheres to the drop. For this is turned around the drop with a wonderful velocity, and it shows the same sight as the drop of silver upon a little tub, which as long as it is polluted with particles of litharge shows its own gyration by a most rapid circular motion of these, until deeply cleansed from these it emits most beautifully the customary splendor. For if Astronomy concludes correctly from the motion of the spots of the sun alone that gyration of the sun around the axis, it is permitted so also to Chemistry to form a similar conclusion from similar phenomena. Moreover, however, this drop only evaporates very slowly. For if you turn to a pendulum indicating seconds with its oscillations, at least 34 or 35 seconds, that is it runs a little over half a minute of an hour before the whole drop disappears. Which at last exceedingly diminished so that it can hardly any more be seen, with an audible crack, which with the ears one easily hears, it finishes its existence, and in the spoon it leaves a small particle of earth.

15.

3. While these things are done, the glowing spoon ceases to glow and becomes cooler. Therefore as soon as the first drop disappears, send another drop similar to the first through the same glass tube to that same spoon, which

with similar phenomena will disappear in 9 or 10 seconds. But there is this difference; this other drop in this case is divided into more globules than the first. which return into one globe with more difficulty, but they are moved from here to there and as if dancing they produce a whistle with their motion in the spoon.

4. Meantime while the iron is cooled more, after the second drop has evaporated, then let go a third, which, with a great motion of globules greater certainly than can be called boiling, it will disappear within the space of three seconds. I observed nothing remaining of solid, earthy matter in the second and third drops, as from the first drop unless there was a manifest impurity in the spoon.

5. If then you put in the fourth drop with the same precautions, this is no longer rolled into a globe, but adheres to the spoon and makes a damp spot in it and with a whistle surges into a true motion of boiling, and thus foaming into vapors it will depart very swiftly inside the space of one second or even swifter, and leaves nothing which is in any way sensible of earth or of solid matter.

6. If after this you send down successively the fifth, sixth, seventh, and more drops to the same spoon now cooled enough so that it can be touched with the fingers with no harm, it will be evident to the eyes that because the spoon is cooler, the drop falling imparts a greater moist spot to the spoon, and adheres to it a longer time before it is evaporated.

7. If in the place of one drop you put in the spoon glowing well several drops, for example six seven, eight, ten, it also makes a globe, but not perfect, the top depressed, nevertheless very transparent. And not less than for one drop slowly expiring without any boiling motion, thus so that some 10 drops stand through two and more minutes in the fire. And they leave a portion of earth, especially if the spoon is left over the fire, so that it doesn't cool too fast.

8. In the same way I compared a deep orichalch phial, the bottom segment of which was spherical, the inside polished. When heated until it glowed, over burning coals, it affected the drops of water in a similar manner, as had the iron spoon.

1), If an iron or copper vase is not pure, but is mixed with iron rust, the experiment either does not succeed or not accurately, because the verdigris and rust impedes the attachment of the water, as will be seen. If this vase is not of pure enough metal, if it is heated red hot, after a great quantity of water (for example 10 drops and more) is poured in at one time, all impurity is rapidly rubbed off by the motion of this water, so that afterward the experiment can be undertaken without disturbance.

10. A little piece of ice is swiftly dissolved on glowing iron, and then it shows the same phenomena as does simple water.

XVI

From this observation various things are understood. First, it is certain that fire brings about the volatility of water, but not by boiling waters. For at first the abundance of vapor increases with the degrees of heat until we come to a certain point, namely, to that at

16.

which water boils. For when the heat increases more, beyond the point at which water is accustomed to boil, the drops of water stand there for a longer time, or, what is the same thing, they evaporate more slowly there. If then the fire is increased more, the water is exhaled much less, and the hotter the iron is and the closer to the fire, so longer do the drops adhere to it. That is, it is evaporated slower so that finally in great heat, such as that of glowing iron, it may be made attached a long time, at least through 34 seconds, and its small part supports for a long while the power of a high heat. Nor do I doubt, if in the experiment a great mass of iron of notable thickness, which therefore does not emit heat so swiftly, is used, then, sufficiently great quantities of water can assume a greater attachment in that same way as this. However, there is no opportunity to try this with large masses. In the second place it appears that the degree of fire at which the water is most of all evaporated is that at which it boils. Third it is manifest that the fire protects the immediate contact of bodies, because the water does not dampen the fiery iron, nor adhere to it. Whence the idea that the drop of water attracts a great part of the fire out from the surface of the glowing iron and it releases the iron from brilliance to motion. Fourth the very hot water endures without any boiling motion. Wherefore it is necessary that at the instant of time in which a drop falls upon the burning iron, all enclosed air is suddenly expelled. Or, what is more probable, the air in such heat is fixed and loses a part of its elasticity. From this, in such a fire the water droplet is left most clear on top, although its transparency is disturbed on account of the many bubbles in the motion of boiling. Fifth, it is correctly concluded from the perfect spherical figure of the droplet and from its whirling motion that the mutual adhesion of the water particles among themselves is greatly increased in such a fire so that in truth the cohesion of water thus is made greater in heat than in cold. But really thus the sixth of these observations suggests that water is changed into earth by a large fire, because always after the complete evaporation of the drop some terrestrial matter remains in the heated vessel. This has not escaped the notice of the distinguished investigation according to the warning of

Boerhaave. For into such fire because of the very light atmosphere all the dust from the surrounding air easily flies together, and it can enter these hanging drops, unless other circumstances advocate the contrary, a subject which we will not discuss.

XVII

In order to avoid all deceit, the experiment is varied:

1. If you loose a drop of moderately distilled spirit of wine from the same glass tube onto an iron spoon glowing with light, this also is altered into a similar crystal globe as soon as it touches the surface of the iron. And in the same way, provided chat it is kept from the name of coals or a lamp which happens to be there, even if it remains in the strongest heat of the glowing iron, nevertheless it does not seize the flame (i.e. does not catch fire). Rather in all these things it is similar to water; it holds itself and stands fixed around 30 seconds or more in this extreme heat. Finally it gradually leaps apart with a small noise, and leaves a small piece of dry earth, which is burned tip a little after by the heat of the iron. And the likeness of carbon or soot glows for a short time, then it splits into white ashes.

17.

2 While the spoon is held over the burning coals the drop of spirit of wine falling takes up t1he flame easily, because it attracts it from the coals, and then it holds it in the bottom of the spoon (i.e. catches fire falling through the flames into the spoon and then continues to burn in the spoon). This can be prevented if at the moment at which the drop is let loose, you remove the iron from the coals, or in some other way cover the flame of the coals. However, when once the flame takes hold, it does not stop burning until all the true spirit has been consumed, because it is done quickly in such a small drop. However in the moistness from this spirit which remains in the bottom of the spoon after the extinction of the flame. the resemblance of simple water is fixed in a long enough interval of time. Afterward it flies into several pieces with a noise and vanishes.

3. However when I have very carefully repeatedly distilled this true alcohol or spirit of wine, in very tall glass jars. I put one drop into the glowing vase, and I set it afire with the flame of a small piece of paper moved close with the hand. This alcohol burns up swiftly in deep (lam.es, and no vestige of a water residue remains. Truly if the same alcohol is protected from the flame, it has the appearance of common water and for a long time the clear globe resisted the actions of the fire. If 8, 10, or several drops are dropped into such a spoon, they conduct themselves similarly, but then they can with difficulty be protected from the flame.

XVIII

I do not understand the spirit of wine in these phenomena. Why does a drop of it not take hold of the flame spontaneously in a very hot iron spoon and in a very warm atmosphere, when nevertheless it is inflamed easily from another burning body? In itself it is clear that the weakness alone of the air is not at fault, because in that same atmosphere flame persists, if this has been excited before with another flame. I learn

however from this phenomenon that great heat does not destroy spirit of wine, nor does it change into its parts, unless the flame approaches. For according to others the spirit through flame can be changed into water, as can be read in Boerhaave's Chemiae. Wherefore it is no wonder that the spirit of wine can be burned from the steaming aeolipile, and therefore it is not rightly concluded from the spirit of wine to water, which I pointed out previously. contrary to Wolf (Para. VII). However many drops of spirit of wine I have burned up thus on burning iron without inflammation, always a small portion of earth remains. But this little piece contains fixed phlogiston. Wherefore at first it wholly exhales liquid, the appearance of soot or carbon springs forth for a moment, then it changes into white ashes. When on the other hand I investigated in a similar manner a drop of pure water, a portion of earth remained, which was not burned. Therefore it contained no phlogiston. However, I confess, several times (although rarely) in drops of water that I used a small portion of earth remained glowing, perhaps a little dust of the wood coals over which the iron vessel was held having gotten into the water, which is able to appear after a quick movement. Perhaps nevertheless another cause exists which I do not know, therefore I conclude nothing from this phenomenon. I am able to do so if the next experiment is performed.

18.

XIX

I show a new method by which the most perfect goodness of alcoholic wine can be determined.

The learned men know that such a mark of character of great goodness is to be desired in alcohol: that which in no way is affected by heat is also thought to be of the greatest use in chemical solutions. That common method which the medicine vendors use for lighting ashes with wine spirits works upon the said defects so that the deed does not appear to be a confutation. However, the brilliant Parisienne chemist, Gothofred the younger, describes a praiseworthy method for the whole thing in a writing for the Academic Royale Parisienne in 1718, in which the spirit of wine is evaluated by measuring the quantity of superfluous water, burning it (of course) in a narrow cylindrical vessel placed in cold water, for after the final fire the water left in a cylindrical vessel may be reduced for measurement more easily than in any other. Nevertheless not even with this very accurate proportion is it determined, although granted that in common practice his method suffices for the most part. For burning spirit of wine heats the water mixed in it, and by this same heat the greater part of it diminishes into exhalation. Gothofred himself in his other calculations in his proposed commentary thought that very pure alcohol is half part water but for my part I do not think so. Because if I held such alcohol in a torch the flame burns very slowly and from its vapor water can be collected. For alcohol, while it is burned, is not made pure, but truly is destroyed and is dissolved into its primary ingredients of mixture water and pure phlogiston. Therefore water is not drawn from the spirit through flame, but the whole spirit is changed and converted into water, as I have said (XVIII). Similarly compared is another thing from his thesis: when quicklime begins to increase in the distilling spirit, demonstrated over abundantly by its watery proportion, so quicklime purifies in the same way the spirit of wine for a certain portion but destroys the greater portion. Therefore, so that we might be certain that nothing in the spirit of wine clings to excess water, it is necessary to arrange the thing so that at the same time that the spirit flies off the water is fixed and impeded in its evaporation.

It is so done with a degree of heat which has alighted glowing iron. For if in the sprit of wine a little water is mixed, this after the conflagration of the first is completed will cling or is moved long and evidently enough so that it can be seen under the form of little clear globes in the glowing spoon. So the pure spirit will be totally consumed so that no liquid remains. From this you are certain that the spirit of wine is pure alcohol. A drop of it dropped upon a glowing iron vessel must catch fire, for if after the flame is spent nothing remains of water. that is the best spirit nor is it able to hold any other impurity. And such a spirit in the Reaumur thermometer rising encheiresin more easily for giving judgment on the solutions of bodies makes the decision more certain.

Similarly it happens in the same way with other and greater spirituous compositions in the described liquors. If a drop of spirit of sal ammoniac for example prepared with the spirit of wine is placed on a burning iron vessel in some way the first outside is covered. through itself probably. It is not burned. but the large globe makes much foam as if supported by tenacious bubbles and it exceeds the mass of the original drop in the vicinity of some hundred each. When, however, this drop is set afire by a flame from a

19.

flap of paper moved towards it. it burns as does the spirit of wine. After the last flame it leaves a very clear drop of water fixed for a long time in the fire. But if the spirit of sal

ammoniac was prepared with urine and quicklime and water in a manner similar to that described above, this never would take fire, but nevertheless foamed and formed large bubbles, which disappeared after a while. It left a particle of water resting in the hot vessel for a long time. In several other saline liquids I tried similar things, and with few exceptions I saw the same phenomena, in the reckoning of which I will

not be long, because nothing now can be taught unless the known nature of simple water is worthwhile to tell over.

XXI

If a drop of olive oil or some other fatty material is put into a very hot iron spoon it never is rolled into a ball but widely adheres to the glowing iron as if it moistened it. If it is put on a fire, in a moment of time (even without the external flame moved towards it), it emits a flame and a great denseness, in which a little while after vanishing it leaves copious black carbon in the hot vessel. Afterwards the image of a coal grows red, and shows copious white embers (earth, in truth).

XXII

Water does not boil in the heat of glowing iron (XV. No. 1) or, what is the same thing, the air leaving does not form bubbles. Both of these phenomena are possible either because the air enclosed in water is not emitted, or (if it leaves) it flees insensibly. In the first case it is necessary that air be fixed with water through fire in some violent way. In the latter clearly the viscous-ness of water is such in that immense heat that it may not require a bubble to rise. This also is true, as the following experience shows: if you apply a cold body for example an iron staff to drops of water clinging without any boiling motion in the fiery heat of glowing iron, or if you move a cold pebble towards it, or even if you drop a water drop from the burning metal swiftly into another less heated vessel, this quickly will boil, and with a boiling motion it vanishes swiftly into the air. Whence it is established that water in great heat does not give up its dry air, but retains it, since after this if the heat is diminished to the point that it can be let out, then the air (clinging fixed with the water between the spaces of water in great heat) is yielded.

XXIII

It follows that in the great heat of glowing iron not all the liquid but only the simple water and the more fixed air is made so. For the spirit of wine swiftly disappears. On the other hand the composition is inflammable, with a water portion left over (XVII). The spirit of sal ammoniac equally with wine as with urine is expanded, inflated, burned in its born essence, swiftly evaporated truly it discharges the more fixed water contained in itself (XX). Olive oil needs to be protected from the flame. It is not changed into a globe. It is attracted by the burning iron. It is very quickly changed into carbon and ashes (XXI). But simple water alone, or that which does not cling in other liquids to that water mixture, is rounded into a globe by the fire. It does not boil, it shines and for such a paucity of matter clings fixed for a very long time. That same water there fixes the

20.

enclosed air. For by water it is done, rather than by the vehemence of the fire, thence it is clear, because the spirit of sal ammoniac in such a heat does not fix its contained air, but permits its great expansion in very ample bubbles (XX). However, we conclude that

some air can be fixed because certain minerals, namely limestone then melted slabs next a red cinnabar made from lead solidified a long time by fire then lime of antimony and perhaps several similar ones, are made heavier by fire. We know absolutely that the acquired weight from fixed air in the mixture can be determined through the Hales experiments in Stat. Veget.

XXIV
Therefore, it has been sufficiently shown that water made volatile is increased with degrees of heat until it comes to that point at which water boils and all very swiftly is evaporated. Then truly if the heat excites more strongly I diminish the volatility of that same water and increase its fixation by the added heat My hope now will be to answer the same objection which can turn away that whole observation: obviously in a great heat water tends to evaporate less, not because it is more fixed when in such heat but because the expelled air does not require the atmosphere to be made lighter by the exhalation of water particles lifting into the air. For there is a certain hydrostatic law: a lighter body in a specific fluid. with a specific gravity, that has great inequality in the proportion of the weight of the fluid to the ascending body ascends with greater swiftness and force. Which thing can be seen by all: water in an atmosphere very rarefied through heat ought to be evaporated less swiftly. But in truth it is evident to me that this objection may be made of nothing in the case presented to evaluate. For (1) it has been sufficiently demonstrated by distinguished Hamberger in Phys. 47'7, that the exhalation of vapors in no way is done according to hydrostatic laws; (2) not yet have we explored to what degree the atmosphere can be rarefied in the dry heat of glowing iron; (3) in the same degree of fire mercury exhales, much heavier than water: (4) a flame in this degree of fire can be aroused as we see, from the spirit of wine (XVII, No. 2) or from the spirit of sat ammoniac (XX) and from fat (XIX); where there is a flame, however, it is necessary that sufficient air enter there; (5) it has been shown besides (XIII) that water expires in the Boyle vacuum. And the learned Krafft observed concerning the exhalations of water in free air and in vacuum, that there is hardly any difference by reason of the quantity given in time. If therefore water in a place empty of air and coolness exhales swiftly, I do not see why it could not ascend in equal swiftness in free air if rather rate and heated. Which reasons contributed also dissolve the opposing fact, so that by nothing can the verisimilitude be overcome. Nevertheless I dig out as the whole deep basis for my argument another experiment I have investigated in w1hich it is proven with certainty that a drop of water in the heat of glowing iron is made more fixed not because of the atmosphere's failing but from the action of the fire. Namely: either a little piece of lead or tin is put into an iron spoon glowing with light. It quickly melts there and is spread. To this liquid metal of lead or tin carefully place a drop of simple water through the glass tube described above so that it will not fall on the convex surface of the metal. You will see this drop, hanging over the lead, dispersed within 6 or 7 seconds. Which water if joined to the lead in the bottom of the iron spoon and therefore laid down in the same atmosphere, it remained more than 34 seconds. Also if one places another drop of water

21.

in that glowing vessel that is put so that it is touched to the lead and so it will not hang over it, you will observe that as the surface of the lead touches it, it flies away with a light motion, and it emits a noise as if the body were dashed against something cold, and then more swiftly with many that if it does not touch lead. Truly, very surely, no one knows

the nature of these things. The heat of the melted lead is much less than of glowing iron, wherefore the melted lead in respect to the glowing iron is called a cold body. And above this cold or medium warm body, a drop of water more swiftly exhales than if it is placed above burning iron, even though the ratio of the atmosphere on both sides will be very perfectly equal. Therefore the rarity of the atmosphere is not the cause of a greater fixation of water in a larger fire.

XXV

Therefore, I dare to propose this new thermometry to the physicists and learned men of
Chemistry, so that in measuring large degrees of heat it will be done equally certain as with an ordinary thermometer in measuring lesser degrees. For it is known that until now with those thermometers that we used, they indicated the degree of heat through the degree of expansion, as much as the enclosed liquid undergoes. Formerly it was established that all the liquid especially is incited into a motion of boiling and its heat is expanded as swiftly as its degree of expansion and cannot be measured better.
From such a thing water and the spirit of wine boil on a small fire to the point that they are not able to measure great degrees of heat. Just then the mercury was added to these, for which often a greater fire is made before it will boil.

But in truth also mercury was despised and shunned for this too much, although from its moderate expansion the heats of metals and melted salts we might be able to find out. Therefore in its place learned Muschenbroek substituted another instrument, which he called the pyrometer, whose construction is such that it is a solid body, such as an iron rod, as long as its extended length shows in proper indication those degrees for various degrees of heat. Since such a very ingenuous instrument is greatly used in physical things and it can measure higher than all others, so the remaining kinds of thermometers can be altogether tested by this thermometer, and also a convenient degree scale is assigned to each. Where however a different degree must be measured in vessels of burning or melted metals or salts, because of its structure the pyrometer is applied with difficulty, in which cases I propose that a method more deserving be devised.

XXVI

1. So let the vessel be hot iron and in addition let it have the degree of heat of boiling water. Onto this a small drop of water put out boils and flies apart completely within one second, or even faster. This lowest and first degree of heat is agreed upon and measured.

2. It is established that with lead in a small trough, of which the greater the mass the better, into which you pour a pure water drop of an equal magnitude as before, the water will not boil, but is evaporated within 6 or 7 seconds.

22.

3. The lead is excited by the heat so that it boils [the Germans say treiberi (drive, push)] ; a drop of water then let loose will not fly apart until after 14 seconds or more.

4. The iron glows so that the whole is made alight: a drop of water in that will be retained through 30 seconds.

5. If then you stir the iron in a furnace anemio with a big fire. a similar drop will he fixed for 34 or 35 seconds. And in this degree of heat the iron remains until melted. For if you detain for several hours a little iron vessel in this same

high heat, so that it is made near to melting, nevertheless the water will not be able to be made more fixed in this unless at the most it is detained for 35 seconds.

6. If in this same iron vessel greatly heated and nearly melted you place one grain of mercury, this flies apart within about 18 seconds. However, in those that I used, three water drops were equal to two grains. Therefore two or three grains of mercury flew apart within 12 seconds. Therefore it is in that degree of fire that the fixation of water is to the fixation of mercury as 35 to 12 or as 3 to 1 in nearness. That is remarkable enough. For with the first, as they say, nothing has been learned easily----to be able to make a drop of very pure water without any mixture as in free air, with the action only of the approaching fire, ever is made repeatedly more fixed than an equal quantity of mercury.

And also with this second method many bodies of metals, earths, salts, and minerals can be explored as to the degree of heat. For as in former times we measured from space in the use of the thermometer, so here in time.

XXVII

However the fixation of water does not increase in infinity with the increasing heat, For iron and copper as long as they burn fix water. Especially in fact they did not fix it more, rather they changed that very drop of water brought together with them with such violence into an elastic state, that such impetus was perhaps not to be found elsewhere on the surface of the earth. Why do you wonder therefore that nature rejoices in changes as the beautiful cycle of all things"! Certainly water at the degree of heat 32° Fahrenheit (when it forms ice) is a solid and rigid form and is the same if that heat increases It is dissolved not into a liquid form, but is changed into elastic vapors, and grows in volatility to the degree 212 of the same thermometer, evidently when it boils. And the fixation again increases with the degree of heat of glowing with-light iron. Then again it was fixed with the iron at a great volatility and elasticity. Who however, determines what was done formerly? Meanwhile from these which formerly I have investigated, it is plain that in the scale of heats, a new fixed point ought to be put, namely that of iron glowing-with-light. When therefore formerly none other than three fixed and constant points of heat were known, namely of salt ice, of natural congelation, and of boiling water, to these this fourth can be joined not unsuitably at the end. For nothing more certainly helps scientists than to have a constant terminal, from which you can measure others. This maxim of Archimedes : Give me the foot that I might measure (da possim figore pendem).

23.

XXVIII

Readers, you do not see me advising that which I indicated in the two preceding paragraphs unless there are possible plans for a thermometer of its kind. How to put together a table of many mineral bodies having their degrees of heat wasn't permitted formerly among my other works, my leisure being small. Meanwhile I show that many chemical phenomena proven by this method are able to be explained. Pure earth and potter's earth evidently never acquire great heat. For a baked dish or similar earthen vessel, heated for a long time and very shiny on a high fire in a furnace anemio, is made very hot but nevertheless it is not much hotter than water in the boiling state. A drop of water is fixed at a minimum when poured into such a melting pot, so that in a moment of time it boils

and is evaporated. Again that which I asserted in XXIV is confirmed by such phenomena, namely that the fixation of water does not depend on the lightness of the atmosphere for the most part. For if the baked dish melting pot and the iron vase glow on that same fire, nevertheless a drop of water boiling in the former is evaporated quickly. However, in the latter it is fixed for a long time. Next the reason is clear also why pieces of earth cannot be found. They endure the fire whole if they are pure. Obviously because they do not attract fire unless to a certain degree and that is why such convenient instruments are made from these discovered minerals. A flint stone, however, made very hot (as much as melted earth) fixed a drop of water much longer. Moreover, several times it seems to me that concerning the experiment described above on Glowing iron in various masses of heated iron (which by chance fortune had offered as an instrument for economic items) the fixation of water did not succeed and I marveled until I observed that these masses of iron had been spread over scores. For with those separated with a hammer, the undertaking soon succeeded. Wherefore scores of iron with common potter's earth and also with simple water assumed the same degree of heat, not greater. Silver has a melting heat less than that of burning iron, but never accurately determined. Alkaline salt glowing but not yet melted into a liquid will resolve distilled water, wherefore from these things and through this method nothing can be explained. But as soon as they are melted into a liquid, they make a drop of water dropped in very elastic and nearly give the impression of melted copper. Wherefore it follows that this salt is made very hot in a state of fusion, and it is clear from these things why the flowing motion of the said chemicals is seen : because it is obvious that they incite an immense fire in a brief period of time and they pass beyond extreme so that even metals are not able to dissolve because of another reason than maximum heat alone. Concerning boiling oil perhaps an exception must beset down from the general rule. since they drive off with great impetus water poured onto them. Whence nevertheless it is not probable that it has same degree of heat as melted copper. About these things and several others which I tried by this method, I am now (when it is permitted to write about these things) more certain than at that time. For more than any other thing it seems probable that the magnitude of the water drops could not always have been very perfectly equal.

24.

XXIX

And also, while I might occupy myself more strongly with the phenomena in these descriptions of water in fire, more often I tried to find out also whether water in this state was impeded in its evaporation by fire according to the Amontonian rule. The truth

remains that even though water has been more fixed nevertheless it stays at the same temperature. Easily one sees (no matter who) that through the thermometer used it can be determined when their masses and, the proximity of the very hot metal will not permit their application when compared with a few water drops which have been tried. Nor have I described all of the methods which someone ingenious has supplied so that I might make use of these toward one goal. I tell only about those which succeeded. It is known that mercury cooked in water does not fly apart, even if a very strong fire is applied, unless after the water touching it has evaporated. When therefore I mixed a very small drop of quicksilver with a drop of water in a heated iron spoon, immediately the mercury was seen in infinitely small balls distributed throughout the water, as if it were dissolved. But afterwards when all the water was evaporated, the mercury showed itself

conspicuously in the spoon. and it flew apart following the water. When therefore I showed formerly (XXVI, No. 6) that mercury in the heat of burning iron is^-more volatile than water, the same is true when it lies in water. It does not fly apart before the evaporation of this. Water is seen in its greater fixation, nevertheless, not to reach the degree of heat which is required so that mercury might be made volatile. Therefore it is seen that water fixed on glowing iron is not any hotter than boiling water, hence I conclude that the Amontonian rule probably remains true in this case also.

Similarly, I poured drops having remained for some seconds in the heat of burning iron from the iron spoon immediately into another vessel. And in that way with repeated diligence I collected a great abundance of this water

consumed from that, so that I might inquire whether its sensible qualities had been altered. However I acquired nothing by this operation unless very pure and clear water which was changed through cold into ice as well as other water. It dissolved salts, it did not cling to oil. On the other hand, if from that very hot ladle I poured such drops over various refines and other bodies not easily soluble by water, I observed nothing that I could not expect from boiling water. Whence again I conclude that the rule of learned Amontonius is probably true, unless the water can be heated to a certain degree. However, my investigation is debated for truth.

XXX

Before I continue to the following things, I ought to describe another kind of experiment with common water upon a strong fire, about which at first I intended to investigate whether a small portion of earth always remains manifest after a drop is evaporated in a glowing iron spoon, and whether this earthy portion is born from the water itself or whether it ought to be ascribed to other causes. I prepared for myself some little twisted glass vessels, which had a circumference about the size of a chicken egg. Into one of these washed and purified twisted vessels I accurately dropped out one ounce of very pure distilled water. Into the mouth of the vessel I put another glass receptacle firmly without mastic but nevertheless sized to the vessel. I made it firm without mastic so that I

25.

might have less fear of the glass breaking. Thus, I set the so-constructed vessel in the said furnace. Learned Teichmeyer gives a description of it in The Chemistries, and more accurately B. Schultz in his posthumous work (Der Chemischen Bersuche, under the name taken from the covers) where it is evident that the jar or iron or baked earth was

placed in a furnace anemio so that its aperture was not on the top but to the side of the furnace, just as the domestic arch is usually placed in the furnace. Into this jar (which in my furnace was fashioned from earth) I placed over a small portion of mud a twisted vessel, and swiftly thus I made it firm so that it could not easily be dislodged or turned around, Before I put the vessel into the furnace I had already made a fire, so that the jar with the mud might be heated lightly. Also it had been turned correctly, set, and placed immovably. I placed an iron vessel within the furnace. and I built up the fire as large as I could so that within a brief time the pot and mud began to glow with light. And after a brief time the twisted vessel glows and quivers. While the fire increases so swiftly, a good quantity of water in the semblance of vapor is propelled with impetus into the receptacle. where it is condensed at last into water again. Especially when the heat comes to the degree when now the jar and mud and twisted vessel deeply and utterly burn, then

the water which is in the bottom of the twisted vessel jumps up and (because of the described structure of the furnace one can observe it with the eyes) it is evaporated gently and slowly, and at last is very fixed. Thus, so that on this fire about a drachma through half an hour and more perhaps without any fume or vapor and without any motion of boiling appearing. When then you build up the fire so that the glass melts and seems to approach near to fusion, then the twisted vessel with a great noise suddenly flies apart and is diffused into fragments. The water from the broken vessel flowing over the glowing mud extinguishes it with a hiss. For truly if you take the broken bottom of the vessel from the furnace and consider it with attention, you will find a considerable portion of white earth.

XXXI

This experiment (XXX) succeeded correctly for me many times but it lacked success several times for it is difficult to make the twisted vessel firm so that it stands completely immovable in the furnace. For if it is agitated or moves even a little then water clings to the bottom and to the sides of the burning vessel so that this is now ruptured before it will have reached full heat and eludes the hope of the experimenter. 1 declined to omit this experiment, imperfect and not -repeated-enough as it is, until I thought of investigating water by a better and more certain method in enclosed heated vessels. Perhaps nevertheless it will give an opportunity to others, something for better experimenting, for which reason I am pleased to add it. However it seems from this that now I have probably taught further above (XXVI) how water committed to a larger fire than of burning iron (for example fused copper or fused glass or beginning to be melted) does not remain more fixed, but at most the elastic vapors are perhaps changed into elastic air. For the same reason a new probability of the Amontonian law is clear: that water obviously even if it is made more fixed in such a fire is nevertheless not hotter. Because after the broken vessel extinguishes the underlying glowing sand with a hiss. plainly besides the cold water (or lighter-heated) is able to hold itself, wherefore in its nature and its heat it is not seen then to be much changed. There will be another occasion, however. for speaking about the fixed part of earth remaining in the bottom.

26.

XXXII

Now the reason for other changes is to show in what manner water, a body in a very fluid
state, is made firm. But for this end it is not yet applied to common experience. From
Aristotle, whose hypotheses I have shown today in two former experiments (III). it is known that the possibility of the change of pure and simple water into a firm visible body could be demonstrated. Another is Boyle_ in whom if the method is correct, it is established that water is frequently changed by distillation into true fixed earth, see
his translation On the origins of form, experiment 9. Another is the marvelous man Helmont, who in wondrous genius teaches that all solid parts of plants and perhaps of animals as well are born from very pure water alone. He fed a tree of five pounds with the nourishment of water alone to the weight of 169 pounds, see his tract On the complexities and mist. Elements, section number 30.

XXXIII

Again the experiment of Boyle succeeds from no one's opinion, since it is perhaps length of patience which one requires to carry out the annoying labor. Perhaps also

because on the authority of Boerhaave, who accuses it of fallacy, since he affirmed that an earthy portion left by distillation in single atmospheric parts and an abundance of terrestrial dust (which is always flying through the air of a chemist's laboratory and adhering continuously to the vessels and to the liquids) must be its origin. With such an objection the Boerhaavian idea has not very much probability, because such a portion of terrestrial dust is required for explaining the Boyle phenomenon. It never flies in quiet air, nevertheless if one wishes to investigate more deeply the truth or falsity of its presence, I urge him to commence with the distillation not in large vessels but in small, not in abundant water but in a small or medium portion of it, and not on a slow^- or little fire but on the biggest one on which vessels can be heated safely, in the method which I have described (XXX). Do it thusly because of an enlarged fire a greater portion of earth is anticipated and because a better atmosphere and more certain dust can be enclosed in a small vase. For me certainly there always remained in the water so tested some white earth, even much more abundant than it is permitted to deduce from the atmosphere.

XXIV

However the experiment of Helmont on the growth of plants through water alone repeated infinitely always correctly succeeds, nevertheless better in one kind of plant than in another. Learned Woodward opposed these experiences set down by Helmont with great zeal in the English Philosophical 7"rarisactinns, year 1699.

number 253, where he purposes to demonstrate that the plants do not increase from water, but from the portion of earth which usually always occupies the water. And which, if it stands in a quiet way; gently is put aside in the form of living wood. For true vegetable material has those living wooden stalks. And he shows in this that plants are nourished more richly with water, with which principle they overflow, much more as it pleases a plant to grow from such peculiar material (so created by God). In Woodward more

27.

modern physics is applied to it, as is clear from the systems here and there. Nevertheless the endeavor of the illustrious Eller outdoes it and he also shows in his communication to the Royal Academy of Berlin that this green wood matter is least common with water, but is sprung from a very subtle phlogiston mixture through the solar rays.

XXXV

It is also permitted to consider in passing that Woodward, while he denies Helmont_a will not show the state of the controversy and would combine the two propositions with themselves, the one of Helmont, who asserts that the solid vegetable parts are born from water. But in the same piece in which he describes the experiment on the willow, he denies with abundance the Aristotelian dictum of transformation. If, therefore, Woodward thinks that the earthy parts of vegetables also are born from the earthy particles of water, it is just so with Helmont, because it is easily conceded that there is a very small quantity of earth in all plants, this which before was concealed in the water. Whence, however, is born the great long part of solids remaining in vegetables which are not earth and also do not lie in such form in water? Therefore, Woodward did not distinguish between a solid or a firm body in general, and a terrestrial body in particular. On the contrary, if he had examined that same green material as he calls earth and which he thinks is intermixed with all water, he could easily have seen that it was not earth, but

richness or fat. And also while he concedes that structures do not increase from such earthy matter, he proposes to himself that these are nourished from earth. This is a contradiction.

They are also less distinguished by him in turn than the great Boerhaave does, a man beyond my praise, and one of those who ought to be venerated since through them it appears not to be a vile thing to be a human. However as Boerhaave was the leader of Europe it easily happens that what he said wrongly and also that which he advanced less accurately are accepted as axioms. Among these I refer to his theory which he zealously teaches on the solid substance of vegetables and animals, to which very pure earth is joined by glue alone not in the way in medical institutions, but in chemistry and they see who wish to think that the proposition is not far from truth that in lesser animals there is no sensible earth, little in the greater and there it clings only in the bones.

However, in cremated bones changed through fire the lime is not the same matter as of living fibres, but rather it fills the interspaces of the vital fibres, dead matter in that living body and remaining destitute of life ; however the solid living fibres have been destroyed by the magnitude of the fire.

Bodies are born from the albumin of an egg without any addition except heat, membranes, cartilages, bones, and true solid parts. For also if I do not deny that something of earth is required in the mixture of solid parts in the vegetable and animal kingdom, nevertheless I think it can be demonstrated in respect to those left more formally than materially for the necessary firmness, and it profits little as it would be an enemy to life because it is lacking in elasticity. However in this passing note I have said that I might show that the reasonings of Woodward detract nothing from the Helmont experiments.

28.

CONCERNING THE WATERY SOLID MEMBRANES OF BUBBLES

For water really is able to be changed into some firm body not in the way of ice and by the observation of chemists (for also into earth it can change but I t ouch not yet this question) but especially the idea is to produce watery bubbles. Thus they form a chance at most so that the method by which water compacts can not be known too little thereafter. Isaac Newton, after he had measured the heavenly spaces, did not disdain to consider the water bubble, so that he might teach nature from its color

alone. He intended a second optics book on the explanation of bubble phenomena.

I fear little to declare publicly that which I draw forth about the nature

of water from bubbles was aroused by the great example of Newton. However,

a bubble arises in all water agitated and moved in which there is some richness. For the foam over the liquids of animals or over the fertile rain if it falls from high or in another way is shaken, what is it if not a mass of bubbles? For what is the reason that this will not turn some to foaming bubbles, which while they show not a durable beauty, they are want to be a very frequent symbol of our fragile and

mundane vanity. At least the better and more constant make bubbles unless some salt is joined to water either fat, acid, or alkaline. The largest and most beautiful of all they make from soapy water. I examine first, therefore, bubbles forming from a little soap.

XXXVII.

Common soap is made from alkaline salt, quicklime and fat mixed with themselves and with water cooked into the form of cakes. Many types of soap are had. There are two principally in economic use, one of the two called Venetian (white); the other called Dutch (or green-black). The former is made from the fat of vegetables, like olive oil. See Ramazzin, On diseased artif. Opp., p.m. 686. The latter is made from the grease of whales. That is thickened to dryness and hardness usually; this is soft, semi liquid and not cooked enough. For which reason the latter is than the former, not only because of the content of oily fat but also because Dutch soap is commonly sold almost a third part superfluous water which does not cling to the cooked out material, which increases the weight and diminishes the price from good causes. It seems also that there is more alkaline salt in Venetian soap, less in Dutch soap. However, whatever difference this may have, the said black soap of Holland is better for the forming of bubbles. Perhaps because it is able to suspend by the nature of animal fat, perhaps also because the salt and fat are not joined closely in its mixture, as I shall tell after this. When I speak about bubbles I wish it to be understood that they were formed with the black soap of Holland.

29.

XXXVIII.

The black soap of Holland, as currently it is sold in the shops, is

(1) for the most part of the same specific gravity as water of common purity, nor for sure does it float on it, nor is it deeply submerged, but its mass immersed in water even before it is dissolved, to whatever place it comes there it stays. For which reason if we dilute it with plenty of water, or this solution is saturated or more dilute, the solution remains at the same specific gravity, truly in common with water. For the oil of soap is lighter than water, salt heavier with lime, and these two are seen in this mixed soap, so that the excess of one supplying the defect of the other make a medium gravity, equal to water. (2) The proportion of oil to water, salt, and lime are not always the same in soap, so that certain ones may be distinguished by this. In two drachmas of this soap which is commonly used, which I dissolved in purest water, I liberated the oil from the salt and lime with the use of spirit of natron, I came to a fairly accurate measure of 50 grains of oily fat, the original fat, because the salt put into this I am convinced was given to the very bottom in the coagulated juice, after a

delay of some hours extracting itself from the salts, it ascended in a fluid form to the top of the water. Again knowing to one part of fat in soap are received three parts of strong lye, and one part of more dilute lye, (Boerhaave, Chemical Principles, II, proc. 73, no. 4) in one ounce of straight lye hangs 80 grains of alkaline salt (Hartley De libon tri t. Steph., p. 77, from the measure of Hales). It follows that in two drachmas of soap are suspended around and at most 30 grains of alkaline salt. Furthermore in four ounces of straight lye there are not but 18 grains of quicklime(Hartley, loc. cit.). It stands that in half a drachma or 30 grains of this salt not more of lime is than about 1 1/3 grains. From which I will not wander far from the truth assuming that in two drachmas of black soap or in 120 grains are had 50 grains of oil; 30 grains of salt; 1 1/3 grains of quicklime, and water not cooked thoroughly at least 38 grains. (3) So that bubbles are formed by this soap, it must be dissolved, or diluted, first in plenty of water. Eight parts of water against one of soap is sufficient. Such a solution I will call soapy lye. Then it results that in one grain of lye there hangs 1/9 grain of soap (for 8 parts are of water, the ninth is of soap) because in one grain of this soapy lye are dissolved if you please 5/108 = 1/21 grain of fat, 1/36 grain of alkaline salt, 1/648 grain of quicklime. (4) This solution, or soapy lye, usually was stirred in some manner, although rain water or most pure distilled water is used, for it grows green, nor may it be seen through perfectly. After which when it stands quietly for a few days, it is wont that some of the oil is precipitated to the bottom, and yet the lye is not clear enough that it allows this solution for the most part to be made lumpy, nor to be mixed intimately (the soap with water). (5) Also this lye exhales in a very soft and long heat of one summer, before which the depth becomes clear, part of the salt separates from the oil, and a salt deposit forms on the upper surface, because it shows the imperfect mixture of oil and salt in this soap. (6) If into such a turbid lye you pour a medium portion of the spirit of a good wine, it is seen through after a brief delay, with the help of the spirit to the mixture, nor does it appear disturbed any more. (7) When the lye through a mediant spirit becomes clear, it loses the virtue of

30.

forming bubbles, or at least only at a minimum, so that the bubbles can be extended and especially they are not colored. The same thing happens if the lye becomes clear after an oily deposit (no. 4).

These were defined by me in explaining the origin and nature of bubbles. Many objections were raised, which are formed easily concerning a thing not enough known or determined.

XXXIX.

So, therefore, one may make bubbles from this lye, to touch upon some pipe in this manner, to extend a hanging drop through a tube, and there is in need of a gentle breath. It rises from a watery, humid, very fluid

non-elastic, turbid body, oh wonder! the membrane hanging on the tube is solid, dry, spherical, steadfast, elastic, pliant at first, very rigid afterward, colored, divided into many layers, and in many other respects admirable. All men who see such an incredible change for the first time are wont to be seized in some degree of admiration. For by a gentle wind the water is changed into the state of ice or glass, and it becomes solid in body.

XL.

So, what I saw in bubbles, others also could see at their convenience. For whom it pleases to innocently play this game, I shall describe the apparatus which I used.

Newton saw bubbles which he thought were produced above the surface of lye, nor did he remove the manufactured bubbles from the top of the lye. Thus he dealt with hemispheric bubbles, not spherical, of which the side settled on the lye was a plane. This hemispheric bubble he covered with a clear glass cup, so that the bubble might remain immune to injuries from the air. This thing was done so that Newton did not note all things correctly, because between the bubble and the lye a commerce intercedes, nor can the phenomena of bubbles be distinguished enough from those which are due to the lye fluid on which a bubble clings. I have decided, therefore: I made a glass tube, the same kind as are attached to little thermometers the other end of which I put into the lye, so that because of the adhesive force, a drop ascended into the tube. Finally I wipe the tube off well, nor does any lye adhere to the outside. I plunged it into a spherical glass ampoule, such as are rubbed by electric machines, through the mouth of the ampoule. Into this ampoule I put the tube, so that the end of the tube on which the drop of lye hung was in the center of the glass ampoule. However, the other end of the tube stuck outside the ampoule and in such a position I made the tube firm. With the tube made firm, slowly I blew through the other orifice of the tube that was outside the ampoule, so that inside the glass ampoule was formed a water bubble, hanging freely from the tube, perfectly spherical and protected from all agitation of the air and other injuries, and that same bubble played out its drama, if all things were prepared correctly, often for an hour or more. However the clearness of the glass ampoule impedes very little in the less you can see them, which I described.

XLI.

By the difference of the lye and of the tube and by the vehemence of the breath being

31.

varied, so is the magnitude of the bubble. Many are the contact points between the bubble and the tube, to which a greater quantity of lye can cling, therefore on it a greater bubble is inflated. When the head of a clay pipe which they use for inhaling tobacco smoke you touch with lye, the bubble can be inflated to 8 fingers in diameter. If you touch glass tube with the thinness of a thermometer, hardly ever is the diameter

of the bubble made more than two fingers. For even if you take up more of the lye into the tube than suffices for such a bubble, nevertheless the bubble is not made larger, but the superfluous lye is collected on its bottom in a drop which adheres to the bubble partly. However, it can be taken away by the finger's motion, without violation of the bubble. However, it suffices for the bubble that the quantity of lye which can ascend spontaneously in an upright tube through the force of adhesion. If the glass tube, and in that of several that I used, I moved perpendicularly in the lye, so that the other end of the tube touches the surface of the lye lightly, the lye in it ascended spontaneously to the altitude of three finger lines, and from that quantity if I blew a bubble, no drop hung in the bottom. If, however, through the inclination of the tube some more of the lye I admitted into the same tube, I could effect from this quantity a bubble equal to the first but not greater, but that which was superfluous was collected in a drop, hanging from the bottom of the bubble. Therefore it is seen that a bubble is not able to be made unless from

one drop of lye. However those drops, because of the diversity of the tube and with a different force of cohesion to it, can be larger and smaller and also make a difference in the size of the bubbles.

XLII.

The portion of lye which fills up my tube ascending freely to 3 lines equals in weight ¼ of a grain. For I was able to know certainly that if all this tube were filled with similar lye, and well wiped off on the outside, I placed it on the balance so that the weight is discovered from the weight of the dry tube I divided the abstract with the number of parts of the tube's length, of which it equaled three lines. When therefore a cubic finger of water weighed equally 311 grains (for lye with water I suppose the same specific gravity, number 34) it will be: 311: 1 = 1/4 : 1/1244, where 1/4 grain of the lye occupies a mass of 1/1244 of a cubic finger. I could through inflating change this little mass into a spherical membrane, whose diameter equals at least two fingers (or more, until it is ruptured), a very small mass. For assuming the ratio of the diameter to the periphery of the circle as 100 to 314, the greatest circle will be equal in its sphere to 6 + 7/25 fingers; however, the greatest circle drawn out makes into 4 parts of the diameter the area of its maximum circle equal to 3 + 7/50 cubic fingers. Which area quadrupled gives the surface of the whole sphere equal to 12 + 28/50 cubic fingers. Therefore with the surface known, if this membrane is placed on an extended plane, it will be considered as a cylinder, of which the altitude is equal to the thickness of the membrane. When therefore (as formerly was shown) all of this membrane is brought from the drop, its mass equals 1/1244 cubic fingers if the base of the cylinder in this way is said to equal 12 + 28/50 cubic fingers, and the altitude of the same, for example if the thickness of the membrane is found to be called x, it will be 12x + 28x/50 = 1/1244 cubic fingers or 628x/50 = 1/1244 cubic fingers. x=(1/1244: 628/50) = 50/781232 = 1/15624 fingers. Therefore the thickness of the membrane in such a bubble will be equal to 1/15624 fingers, which

32.

thickness haply coincides with the 66/1,000,000 in the Newtonian tables. So, that which I propose about the bubbles ought to be understood from such a bubble that was extended into a sphere from 1/4 grain of lye to a diameter of two fingers and whose thickness of membrane is 1/15624 fingers.

XLIII.

Therefore, first I observe that that thus born and determined in the bubble is that such lye indeed is changed into a solid and firm membranous body. That sense teaches which distinguishes clearly a fluid body from a firm one. For if it touches on something so that you take up more of the lye than suffices for one bubble, this superfluous portion collected in the bottom of the drop differs greatly from that same bubble so that it is permitted also to remove or to wipe off this drop from that with the finger. If at first the drop was wiped off, a new drop in the same bubble is never again collected, but a bubble of the same thickness remains obvious to the sense and up to the time of its bursting. Therefore Newton, who explained the succession of colors from successive diminishing of the bubbles because of water flowing away, did not correctly observe the bubble. Also because of the causes indicated (40) he could not do it. For a solid body cannot pass away or run off, nor for a fact do the parts of the bubble pass away. Rather all bubbles have the suitable properties of solid bodies, that complete themselves, that confine other fluid liquors in themselves, that all regions of the particles not indiscriminately can be separated from themselves. So that I might demonstrate this to the eye, I considered whether ,I could fill such a bubble in a glass flagon with liquid, but nevertheless in such a fragile bubble it is difficult, unless with smoke. Obviously through the same tube from which the bubble hangs the smoke can be blown as densely and abundantly as you please. Those that are infused with tobacco smoke are done without injury when the smoky draught intrudes from the cheeks through the hollow pipe through the tube into the bubble. This smoke penetrates the bubble very little, and it is confined among its membranes not differently than as if it had been enclosed in a glass, until (the bubble breaking) it expires at once. Similarly it happens that if we prepare the bubble in the winter time, cold air under the form of vapor is visible in the exhalation of the lungs, then it is contained in the bubble in the form of fine mist, nor does it pass through its pores. And it is pleasant to the glance, in what manner exceedingly fine and many colored bubbles of fog and dense vapors can be agitated within, opaque bubbles especially because the colors described by Newton as such opaque bubbles are reflected

through the enclosed smoke much more brilliantly, so that the shining recalls to mind a very beautiful star, all glory of which perishes if the broken fragrant smoke departing shows that it is ugly within, and with the mark of man's splendor makes emblems of misery. If therefore the membrane of the bubble is not solid, the smoke, at least, it contains, and rather transmits the form of fluids. For a smoky body intruded into water or fluid through some tube is at least contained in that tube but the following soon demands better hydrostatic laws, as from the fluid it is customarily extricated in the Persian manner of inhaling tobacco smoke through a water medium,

33.

described by Kaempfer in a charming, incomprehensible etc account which shows that it may be imitated.

XLIV.

Furthermore this membrane is dry, nor does it moisten a dry finger which touches it, especially if you bring no more of lye than is required for forming the bubble (37). For if the lye is abundant, the particles of it flowing to the side in such a way dampen the finger and especially in the really wet drop they are collected within on the bottom of the bubble. If onto such a dry bubble you pour a drop of water gently and moderately, this flows over the surface of the bubble just as over a glass and it again is collected in a drop, whence it can be wiped away with the finger. On the other hand it destroys it completely if the gravity is enough to overcome the cohesion on the bubble. This water poured on is not mixed into the membrane. It does not melt it, nor does it adhere to it. Whence it is certain that this membrane is truly a solid and dry body.

XLV.

Moreover, the membrane of the bubble is not in a solid condition but elastic. For it does not resist in that way its expansion, and it requires a state so that it may be extended effectively, but also it always restores itself into a spherical form if its figure has changed from external causes. For with the finger (which ought to be dry) a small pit can be pressed which springs back with the finger removed. The bubble can by a motion of the tube through the external air be elongated by the agitation, curved around, made thin, compressed, but nevertheless it always restores itself into a spherical form as soon as the mutating cause ceases.

XLVI.

The bubble has at first a perpetual struggle for bending itself.

For if the tube from which the bubble hangs remains open (however, it is easily obstructed by saliva flowing from the mouth into the tube while inflating) so that the external air through the tube into the bubble is freely kept going and returning, and the pressure of the atmosphere is equal,

as much on the outside as on the inside surface of the bubble, nevertheless the bubble successively restrains itself and the accelerated motion is diminished, expelling the contained air through the orifice of the tube, until to such a point it has contracted that with its evanescent cavity it falls condensed into a drop from the tube. That is seen much more evidently if the bubble is filled with some smoke. For the smoke is all visibly expelled through the open tube as if through a fire-place from the elastic contraction of the bubble.

34.

XLVII.

The elastic contraction of the bubble (46) especially, as long as does not yet shine with colors, has joined flexibility and tenacity so that it is not easily broken or divided into parts, but that is irritated in a thousand ways and it permits itself to be perforated anywhere (not in a sharp way but with blunt instruments which again extracted the bubble is by no regard to means destroyed but the wound is made quickly and freely closed). In regard to which, however, the longer the bubble lasts and the more clearly colors begin to appear in it, it is made slowly more rigid, so that it cannot be punctured anymore without a fracture. And a rigidity is observed greatly in the black places of bubbles, as those black spots (described by Newton in Optics, Book II, p. 1, observation 17) are not touched very lightly with a small pin without immediate rupture. Rather if the bubble is touched in these places it immediately bursts with an audible sound and is very swiftly thrown apart in infinitely infinite little particles. However these particles against the whole circuit of the periphery, and they are thrown with great force, so that to 3 or 4 feet unspun they are often propelled until at last I see the graceful forms of very fine drops. That space which can be measured ought to have a dark vault, which is lighted only by one beam through a little opening; if a bubble is broken in that beam, one will be able by the sight of the eyes to seize upon the motion of the flying particles from the bubble. This is another type of elasticity in the bubble, evidently explosive, which is opposite from the diameter in its contractivility (46).

XLVIII.

This explosion of the bubble with similar phenomena touches wholly

upon that marvelous explosion that we observe in the said glass drops. For such a drop of its body rudely pounded with a hammer does not fly apart as soon as the tip of the step is broken but soon the whole bubble is dispersed with impetus into a cloud of dust. However a similar bubble does not cracks unless it is touched in the black spots; in all other points it sustains a stronger impulse. However, this explosion of particles always proceeds to the center rather than to the periphery. For if within the bubble another bubble is formed through an intruding tube on the side, this interior disturbance breaks up at once the exterior, however -- the exterior first breaking strikes the interior less, nor does it move in any way. That holds itself in a glass drop similarly, see L. B. de Wolf.

XLIX.

There is therefore in the bubble a double struggle, doubtless the first centripetal (46) which especially manifests itself in not yet colored bubbles or also in parts of colored ones which are destitute of colors, and in this state it is seen to be greater than the opposite struggle. However the other is centrifugal (47) explosive, strong, in which all or at least particles individually withdraw violently and are dissipated widely, which seems to reside

35.

in colored bubbles and especially in the colored parts, moreso however in black spots.

That in which there is much dilute lye from which a bubble is formed, i.e.

that in which you put more water in respect to soap, in it the centrifugal and explosive struggle is stronger, for in no way does the bubble explode faster but its particles are projected more widely. That in which lye is more saturated, for example the more soap you put in in respect to the water, the centrifugal struggle is less in this, so that if such a bubble is broken it explodes very little but it makes some cracks and the image of a spider's web or of a spider's rich membrane falls from the tube in the larger pieces. On the contrary, the more of soap that there is in the lye, the stronger is the centripetal force, so that it contains itself easily in a smaller mass, expelling the contained air. The centripetal force is much smaller and hardly observable if you mix a lot of water with the soap. Whence it is clear that through the diversity of aim which we have, the matter of the bubble by various means must be tempered.

LI.

Next (50) it must be concluded that the explosive quality of the bubble depends upon the water; its very tenacity and centripetal constrictive quality is from the soap, especially since the origin of soap is drawn from oil. Wherefore even the diversity of oil is seen to make a durable diversion in bubbles, so that soap in which there is animal fat usually forms the suggested bubbles more constantly and less swift to explode, than that which was made from vegetable oil (37). And it is understood why soapy lye in the bottom of which olive oil is placed after a long period of period of quiet makes less constant bubbles but more explosive ones (38, no.4. 7)and in such a manner the spirit of wine blended with lye enlarges greatly its explosive faculty (38, no. 6. 7) which last phenomena I will explain shortly when I will add that the lye of animals, for example saliva, diminishes the explosive force and aids the contractive force.

LII.

So the centrifugal force is in those parts of the bubble which are colored, especially more in the black spots than in the clear and non-colored and the centripetal force more in the clear parts than in the colored (47). However the centrifugal force depends upon the water as the centripetal force is seen to follow from the oil (51). Some division is made between oil and water in the bubble membranes, and the mixture is disturbed with lye as soon as that passes into a state of solidity. So that it might appear more manifest, it is now permitted to indicate briefly the origin of variegated color in bubble membranes and why they manifest themselves not always in all bubbles, never in the beginning, and not in all parts of the bubble. Newton thought that this followed from the successive thinning of the membranes. He supposed such a membrane not to be a solid body, but to remain water particles in a

36.

fluid state and also from the law of gravity to flow to the side of the bubble and the thickness of the top to diminish continuously and from which diverse thickness to follow a diverse order of weakening and reflecting rays: Book II. Optics, part 1, observations 17, 18, following. In which if I seem to contradict a great man, let the reader take into account that the bubbles have been considered by me on the plane of another viewpoint. In fact Newton did not measure the thickness of the bubble, but concluded it from the similitude of colors with those which show between the spaces of two glassy hollows. In fact he did not remove the bubbles from the lye. If the properties of a bubble alone were assembled he might have seen accurately. On the contrary, I measured the elements of lye first in its proportion and also I have determined the thickness of its membrane by a very certain method. I was protected from error as much as possible before I dared to conclude anything from my observations.

LIII.

Obviously the membrane of the bubble is either simple or homogeneous, but as soon as it changes from the fluid state into a solid state, it is obviously loosely composed of three skins or layers. The first skin, external, highest, which at all points encompasses and clings to those inferior remaining ones, is oily and fat, in which the colors described by Newton appear. This one is contractible, the least explosive, and secures a flexible elasticity with the two other underlying layers, so that they are not easily broken by an external force. For as long as this external membrane is extended equally over the whole bubble, so long is the bubble not easily broken, as said in the first part of (47). After a brief delay this first exterior one contracts into diverse places and then in turn the lower part of the bubble is made thicker while the other two layers persist or flow away very little. While, therefore, this skin contracts itself greatly and flows away, necessarily it secedes from the underlying remaining ones, especially at the top, and to some extent makes the other two bare, which one sees through the upper opening. However, varied colors appear in this exterior flowing away skin through its diverse thickness, while the two left underneath preserve the same color constantly.

The second layer is white, and it always reflects white light, nor ever shines in other colors. This Newton saw correctly, but he described it as a clear spot which manifested itself under the color white. This layer after the first secedes contracts itself also and bares the third and last. Through the opening it can be clearly distinguished from the second. This other layer is the salt and earthy part.

The third and inner skin is very clear, almost to the point of being invisible, the image of a black spot appearing if it is viewed from the side. It never reflects any sensible color. It is very fragile and quite rigid, so that if it is irritated (very lightly touched with a needle) soon the whole bubble is scattered widely dispersed in infinitely small particles. Also this never contracts itself alone

Or flows away, but is the same wherever you look. It remains solid, colorless, constant, and very elastic as much on the top as to the side. The whole is moist.

37.

LIV.

It is clear that the outer shell is oily because the lye is more pure and steeped with much soap. This external layer is thicker, more splendid, and also has wider zones of color, persisting longer. If the water was more abundant in the lye than soap then this outer membrane is very thin, so that it can cling not only at the top but in several places it exists and creates a little net. Swiftly it disappears, nor is it so elegant, nor does it preserve colors so long. Therefore there are born black spots on the bubble more swiftly and they can be seen more clearly. At last, if the bubble endures in a quiet way without injury of the air, all of this exterior oily membrane is contracted to the lower part of the bubble and it pollutes it in the bottom with many colored oily spots so that with such as are seen in that layer, one can not doubt that the nature of it comes from the exterior oily skin.

LV.

Moreover, if now this exterior colored by the interior underlying layers begins to secede, the distinction of these is very clearly discerned, if this exterior layer is agitated by a breath from the mouth or another motion of the air. For then it appears very clearly that the third inner colorless layer is moved by nothing. However the outer layer in various fragments secedes and a cloud image moves over the immovable colorless skin with an irregular motion by a strong wind of agitation, nor does it preserve the order of colors any longer, now ascending now descending it is applied in various parts of the third layer. That third layer then obtains throughout the inner spaces of the superior layer in all places wherever you will, equal to the black and also appears to be of the same thickness. Which phenomena even the illustrious Newton himself does not deny to have seen.

LVI.

More certainly one can take in with the eyes this secession of the oily shell from the watery one, if a non-spherical but plane sheet is prepared from the soapy lye and is placed in a vertical position. For example, if you put a glass tube or earthen ampoule (which has an orifice at least 6 or 8 lines in diameter) into the lye and again withdraw it, thus over the orifice of this tube a solid plane membrane is extended, which shines with no color at first and a little after it is separated into the familiar three layers so that it is separated from the sphere of the bubble so manifestly that no doubt of its thinness can remain.

LVII.

Wherefore also in lye more perfectly mixed it is obvious that its oily and salty and watery parts have a more firm cohesion. Thence so that fat can so easily secede from the remaining elements that no colors even appear. Such perfectly mixed lye is evident in the lymphs of healthy animals. For if a portion of saliva of a young, healthy, hungry man

38.

is expectorated onto a glass disc, and is placed in a tube, extended into a bubble, this is able to be made large and elegant if you blow with caution, also enduring for a very long time, nor very fragile, however bereft of all color. On the contrary if such a bubble of saliva freely hangs from the glass tube, never does it show any color. For by the method above indicated (42) the thickness of the membrane of these saliva bubbles I have recalled several times under account, where it is obvious that it also has a tenacity. Some color ought to show forth according to that second Newtonian table about the thinness of the layers in the colors, but it never arises. Because in this salavic lye all things are perfectly mixed, fat cannot secede from the remainder and also that does not show a peculiar colored membrane.

Also this bubble of saliva has this peculiarity, that its elastic contractibility that I have named centripetal force above (49) is much more than the centrifugal force. For never, even if for an hour or more it will stand, does it explode into that thin shower, but when it explodes it collapses in cracks as if moving and the image of very sticky mucus or the image of a spider web falls from the tube (see 51 at the end). Similarly then the reason is clear why lye soap to which some spirit of wine is mixed shows absolutely no color if it is expanded into a membrane. Because the spirit of wine joins the elements of the lye more closely, and does not permit the secession of the oil from water so easily (51 &38, no. 4, 7).

LVIII.

Those things which I have observed about saliva are also true about urine. It is fitting for me as a doctor to intersperse this medical observation, which quite often experience teaches to be true and to bestow the prognosis of diseases. Healthy urine scarcely ever foams, or if some bubbles are born in shaking it, these perish again very quickly. Healthy urine is truly a liquid excrement and unsuitable for forming solid parts.

However, in catarrh afflictions especially of the head and where a healthy lung is changed into blood, the urine foams very easily and it keeps the foam often for several hours. This sign is then not only of the excremented parts, but that nourished lymph water is separated as with urine. This foam in the urine is not always colored, but very clear white, as I have very often observed. When however this foam in these bubbles collects the color of iris, it designates a difficult disease, because it declares that the whole mass of liquids are mixed imperfectly, from which the saline and fat parts secede, and they disturb the necessary mixture of nutrition and

of life. Similarly the bubbles which appear in milk, in boiled milk, in blood sent from the veins, and in well-cooked and fermented beer, rarely are colored, but always are clear. Whence I conclude that

in these liquids oil and water are more perfectly mixed so that the oil cannot easily raise a special layer and show colors.

LIX.

It is also seen why in cold weather the colors in a bubble appear more quickly

39.

and clearly than in the hot summer, because obviously cold water dispatches oil quicker from clinging together than hot. It was on that day the 7th of March, 1754, when a Fahrenheit thermometer descended in this place to 7 grains and also 25 degrees within the point of congealing of water, so I knew by repeated observation. And this which I write at the time in the year 1755 when sometimes a great cold oppressed us, it descended to the 22nd degree of the thermometer within the point of congelation in this city, when recent publications in other regions indicated a much more serious cold at the same time. Nevertheless in length of chilly time the prior winter before this one was in excess, and it likewise gave me an opportunity for repeating some similar experiences.

LX.

Finally I might mention the colophon for this search about the colors of bubbles, that Newtonian measure that gave the thinness of the sheets concerning the colors. He did not show colors of the bubble to be seen in the whole bubble but only the exterior oily sheet of them. The thickness of the whole membrane which makes up the bubble and also for all of the layers alike if tried by the method above (42), it is recalled, is always too thick for any color following the rules of Newton to be able to appear. On the contrary, if the thickness of the exterior oily sheet only is measured, it compares exactly with the observations of that illustrious man. However, so that the thickness of this exterior sheet can be measured it must be directed in the following manner: (1) In one grain of lye are 5/10}3 grains of fat (38). (2) However 1/4 grain of lye is required for one bubble of which the diameter is 2 fingers (42). (3) Therefore in such a bubble there is 5/432 grains of fat. (4) The specific gravity of fat to the specific gravity of water is as 9 to 10. For such with many attempts was seen by me, so that I am able to come to this proportion without great error. Nevertheless, I concede that it is necessary which every way the water overpowers by gravity that not in all fat is precisely the same proportion able to have a place. Meanwhile this necessary diversity is not such that it can disturb the conclusion of the reckoning much. (5) Wherefore when a cubic finger of water is equal to 311 grains, from the arithmetic law the cubic finger of fat equals

279 1/10 grains. Because of the usefulness of this reckoning it is assumed that a cubic finger of fat equals 280 grains. For such a little difference that never is exactly demonstrated in my reckoning is not able to be known. (6) Therefore it must be asked what mass, for example, what part of a cubic finger do 5/432 grains occupy? Namely however the little portion of fat which is contained in tile bubble is the mass: 280: 1 = 5/432: 5/12U960 = 1/24192. (7) So small a portion of fat namely 1/24192 cubic finger was expanded into a thin sheet, which equally at first surrounds the whole bubble. Truly the surface of this bubble is, as above was shown (42), equal to 12 plus 28/50 fingers squared. (8) If therefore the thickness of this oily sheet is called y, it will be 12 plus 28/50 y= 1/24192

cubic fingers or 628 y = 1/24192 cubic fingers whence it is had that y= 1/24192: 628/-^:: For example y = 50/15192576, and if divided by 50, y = 1/303851 plus 26/50 fingers. (9) Therefore this thickness of the outer oily layer as long as it is not contracted or colored

40.

but equally is extended over the whole bubble = 1/303851 fingers (for it survives a small fracture, the deed does not injure it), which coincides almost with the 3/23: 1_,000,000 from the Newtonian tables. Nor should it have color,(unless a splendid whiteness) which it truly does not have. For in truth soon thereafter especially after the inflation is made nearly nothing, or somewhat white, or a splendid color the bubble has. (10) When after this delay this exterior sheet in position over the interior watery one diminishes itself, and successively disappearing descends toward the bottom becoming more thick, then the colors left are described by Newton in the order in which they are accustomed to appear. Thus so the colors which are in the Newtonian tables are the first and best, since the tops of the bubbles are closer than the opposite.

LXI.

Since, however, the whole membrane of the bubble obviously stationary becomes three layers for the reflecting of color, it becomes a useless task to explain the phenomena by the Newtonian law. For this whole membrane is 1/15b24 fingers thick and this thickness almost coincides with the 66/1,000,000 from the Newtonian table. It seems to differ too much from the thinness that that illustrious man requires in his calculation. The said Newtonian colors are reflected not by the whole membrane of the bubble but only by its exterior oily sheet. Wherefore those things which I think about the colors of bubbles, discussed in 53-60, will certainly be demonstrated. For often, in danger of error, people

will argue about the thinness or thickness of the sheets saying that possibly it is the color not from the whole membrane but from its one layer reflected. Which thing is often done by Newtonian authority and no one changes it.

LXII.

On the contrary, it can be very much doubted whether any color is ever reflected in pure water in which no oiliness is impregnated(which water is certainly difficult to obtain) in a sheet extended either thin or thick, unless some shows elsewhere or in dark colors that might be ascribed to part of the saline or the earthy particles

contained n the water. The very black spots of the bubbles, which are in the watery parts, and the saline parts above are diminished from entwining, as shown above, and have no color -- not because of its thinness because many are thicker than Newton shrewdly thinks them to be. From conjecture alone he thinks the thinness in these black spots to be about 3/8,000,000 fingers, when nevertheless my method given above for examining the thing, most certainly shows that these very black spots of the bubbles are not thinner than around 1/17,000 fingers. Besides, these spots are always of the same color, whether they are born on the crown or summit of the bubble or to the side of it. Of little significance--they are very black if seen obliquely, or very clear if seen directly, constantly un-colored, reflecting no light. Wherefore, one can doubt whether simple water ever reflects any color if it is considered pure, whether its skin be thicker or thinner, and whether all of the rays are reflected by the fat alone and the phlogiston especially appears mixed. However, nothing lacking in the water, color is generated. For if from lye equal in weight to 1/4 grain

you inflate a bubble of the diameter of two fingers, one or several black spots arise

41.

in it if the exterior oily layer recedes from the aqueous interior one, as seen already. If, however, you inflate a bubble from the same portion of lye that is not more than one finger in diameter, similar spots also arise perfectly of the same color as in the first, indeed very black and very clear, in this as soon as the exterior oily layer recedes. But truly this watery layer which forms a spot in the bubble mentioned before is of a thickness about 1/17,000 finger; the watery shell which forms a black spot in the latter bubble is less about 1/3,000 finger. Therefore the aqueous layers of them, with thickness of 1/3,000 finger and 1/17,000 finger, show the same color -- obviously none, unless very black. Tile chemists undoubtedly have taught this truth for a long time and demonstrated it with experiments--if primarily there is no phlogistic matter in bodies, no color is generated, The difficulties with the doctrine of Newton about the colors of the thin sheets are conciliable in this way, or at least the limitation of the Newtonian doctrine is approached, but not mine as I see it.*

*That which is said about the reflection of light from water is not equally true about refraction. For all water and pure ice breaks up the rays emitted, as we all know. On the other hand, not all water breaks it up under the same angle, so it is seen that something is different in the water.

Whoever lives by the Rhine river and especially the sailors toiling a trade over it, taught by experience, know how to distinguish by color alone the ice brought to the Rhine in wintertime from the various lesser rivers. For if winter is harder than usual, the enormous force of ice in some way arrives at this great river, not always born from the waters of the Rhine (if the surface thickness is to a rare magnitude), but brought from other rivers by a slow motion towards the sea. Which ice not only makes the crossing of the river often dangerous or impossible, but also with its abrasion makes great trouble on the banks, wipes off trees, scours the fields, knocks down houses, and breaks down the ramparts if perchance the masses of the greater ones are to no avail. Or the violence of the river , itself directs its impetus to such objects. However, at first the boats are encircled by these mountains born of ice and conducive to shipwreck. For which reason the sailors are accustomed to watch carefully and to observe zealously whether all that in that year will descend is descended, or whether they ought to expect a new abundance of it. For so long as they fear these things, they believe their journey not very safe. However, they know from the color which river transmits its ice, which less. For all ice is either clear or opaque. It seems opaque when infused either with earthly impurities or with many air bubbles from which they get no sign. That ice is truly clear that is from the purer water on the surface of the river. With a great chill often it is congealed one or several feet thick, increasing instantly, and nevertheless it stays clear. However, sailors observe that this clear ice from the Rhine waters always has a sky blue color when condensed. However, the clear ice descending from the Moselle river turns green. And from all our lesser rivers, as the Ruhr river and similar ones, not too much a white color or a pale green shows. This observation of the sailors is certain and often repeated by me as often as I have had a home on the shores of the Rhine, also this year, 1755, in which the winter is more inclement, so from all the rivers of Germany thus to the father Rhine inject a crystal bridge, and at last the diffraction carried an incredible amount of ice from different regions through our vicinity to the sea. I found the occasion for inspecting the

42.

same thing more accurately. However, this clear ice, as much the blue Rhine as the green Moselle, when it freezes shows the purest water, neither peculiar of earth nor of salt, nor show any sign of fat from which this diversity of refraction can be understood. Rather because this color is always similar and steadfast in a single year, it isn't

believable in the mixture because merely the abundance of which the proportion and quality will not always be the same. But the cause of the thing lay in the water itself, where the water contrary to rays of light either more powerfully or more loosely breaks up the rays than others -- therefore a diverse density, hardly measurable with common instruments, nevertheless it shows with color. Assuredly fountain water is seen, which for a long time before , has flown from the caverns of mountains, to acquire another nature when it is exposed only to air, formerly not enough known or declared. For the softness and durability of water no one, at least not correctly, has ever exposed. In truth, the very diverse nutriment of herbs in the variety of water, and the flesh of fish so varying for the variety of a large river in which they live, and perhaps the habits of men and the diseases from the water which they daily drink through necessity, and many other things are taught which doctors understand through experiment. Namely, that there are various essentials of waters, and they indicate a diverse habitation in respect to other bodies. Whoever of the Aleutians in Valachia and the Tyrolian mountains drink of the fountains, they suffer from tumors. In Frisia once upon a time there was a fountain of sweet water which having been drunk, infested the stomach and caused a lameness of the knees or ankles. Similar fountains are in Gaul today. Nevertheless if this water is examined by the common and formerly used method, nothing shows from which such marvelous effects can be explained. Wherefore, as for other phenomena, and perhaps also the relation of light to those, which we notice. For the reasons mentioned the utility of this method does not recommend it.

LXIII.

These primary phenomena are of water bubbles, for the forming of which there is a certain theory about the nature of water, They throw in a more certain basis for this which they have more truly observed. For occupied always in seeing these things correctly, I have a measure and a counter in

my hands, and so much is allowed me, that I might be returned safe from false senses.

LXIV.

At first, therefore, while from the soapy water through the inflation alone there is a solid membrane, none will be that wish to deduce this solidity from a portion of earth intermixed, or mixed with a little alkaline salt materially, even if it is true, that the small portion of the same fluid if mixed with many solids, by these haply it is absorbed and in some way loses the nature of a fluid. If a lye soap dilute is gently thickened with heat and the fluid particles carried off into the air leave solid parts, these wholly near to themselves successively brought to the soap make a solid mass, it is said that no water

43.

particles are in this intricate mass, because of the paucity they aren't thought about; Nevertheless as this is done, it is necessary that the quantity of fluids are much less than of solids. In this case, however, the proportion of earth to water is insignificantly small, about 1/648 of the total mixture makes (38, no. 3), and the first salt appearing in the soap makes not more than 1/36 of the whole mixture, so that undoubtedly from these in no way may one seek the fundamental of firmness. And in such lye, when it is inflated into a bubble, nothing is added, nothing is taken away, but that same matter which formerly constituted a very fluid lye and very little thickened, without any material admitted (unless by chance from the air) is a solid firm membrane. Wherefore , the principle earthy materials swimming perhaps before now in the lye must be reckoned at least, but only for the same kind of mutation through inflation, that is, through the determined motion of induction. The beautiful experiments of Boyle, which he has in the Tract concerning fluid and firmness,

also confirm that the firm body effects a change in liquids only in the direction attempted.

LXV.

The physicists conceive of the matter of fluid in a different way,

while others look for the thinness alone, figure, mobility of the constituting parts, as several Cartesians. Others, however, suppose motion at the same time an actual intestine in fluid wherever it pleases to be necessary (as Boyle and those who followed him, especially Stahl). It seems to me from the thinness and figure of mobility alone no notion of fluid is born, but at the same time a mutual attraction is necessary in these small particles, as several have recently assumed. That is, as they have a perpetual force to cohesion, Yet nevertheless they do not cohere, wherefore a heap of very thin sand or fluid of gypsum never can be described, because its particles exert no sensible force. This force, however, ought to be against all areas in un-dispersed fluids, so that the particles composing the fluid are in a certain state of liberty, and all vicinities it draws in equally, nor is it peculiarly stronger in the direction against one or another region.

Truly then a firm body is seen by me to have very small particles, which are not only in the attempt at cohesion, but truly they cohere. Indeed they are continuous and they draw themselves to the necessary point stronger from one side than from the other. Hence they have some common center of attraction and cohesion, which struggle is not free and un-dispersed, but is determined in a certain way. Wherefore, as it is made a solid from a fluid, often not another thing is wanting unless a certain motion of the actual, which struggle formerly determined the wandering of particles toward one direction.

LXVI.

When a spider weaves a web in which trap a flying insect is accustomed to be captured and conquered, he forms his thread from sticky wetness with only attraction, that is, only motion. For the juice from the glandular pores secreted in the maw through

44.

a single motion of his body he changes into a firm thread in a moment of time. In such a moment of time, the thread of spiders born from liquid even in its thinness is one of the most firm bodies of the world. Not by any material added or subtracted, nor by coagulation, nor made by drying, but only the form of the dampness is changed -- namely, so that the particles in one line attract themselves, on which the spider depends. When formerly, as long as they were liquid, they had an undetermined and uncertain force of attraction. In the swift moment of time, this filament appears to solidify not from drying out or wetting down. The thread is equally firm or solid as first appeared as after some hours or years. Similarly, one can observe that in several insects.

LXVII.

For in a fluid, so long as the attempted undissipation of particles against all regions is equal, this can have no effect, because the effect impedes the effect. The effort of trying is equalized, to the point truly that fluids do not cohere for the reason that the force is innate, from the theorem of learned Hamberger in Physics, # 193. Wherever you wish the force in addition acting in the dampness (for example, the force of gravity) this effort within the fluids is strong to overcome, whence the fluid itself is not able to cease, from the Aristotelian definition that it does not have within itself a sufficient reason for its form. From which principle -- the equilibrium of fluids

all rules of hydrostatics depend. In truth a solid body has one common center , or certainly some common center of cohesion. That is, it has a first point or some primary point against which all of the particles tested are arranged. Wherefore, formerly no solid body was observed that did not have some structure in its smallest parts, that is, a peculiar way of cohering to itself, and thence following a peculiar figure. All salts, all stones, all sulphurs, all minerals, in their least parts, are crystallized. Metals, in addition, are stratified or foliated in a peculiar way, as appears from their fractures (see learned Cramer in his example). All glasses consist of long crystal filaments which concur in some single point, as in a glass tear.

Learned Feaumur (M.A.R. 1730) adds a singular organism from the least earthy particles; water itself, when it is changed into ice through cold, solidifies not irregularly but in a kind of crystallization. And I say nothing about vegetable and animal fibers, because it is a well known thing that they all have their own structure, and if I add several now I would seem to wander past the limits. On the contrary truly the smallest particles of a fluid body, however many were able to be investigated, exhibit no regular and constant figure. That is, they have no structure or constant way of cohering, but nearly all of the figures are full, unless you wish to adduce that perhaps a globular figure of liquid fat is dispersed in the water or Leuwenhoek's globules of blood, the figure of which depends upon action from the vessels and other external causes, nor can it be had for a constant because it is accustomed to be much varied through the variety of vessels and motion. And in this same bubble, which I have described formerly, the single membrane parts constituting some peculiar order preserve a sight for the eyes. The outer shell is obviously oily, the inner one is watery, between these in the middle is the saline one. And it is obvious to the sight that here where the incomparable Stahl predicted, and correctly

45.

expressed, if bodies of diverse nature be mixed, they draw them selves to one side. Obviously water of itself does not attract oil, rather it flees. If however first some salt of calcium is joined with oil, then water intermixes with the salt or from the association with the salt also draws oil and associates itself with it. Certainly salt is a medium and between the others joins these heterogeneous bodies.

LXVIII.

As such an attempted direction in fluid is not always completed, it is necessary that the external motion appear to resemble the threads of spiders in the example brought forward of the soap bubble. Once a flow is within something, this determination (and for that reason) becomes a solid, the spirit movement or force for seed. Chemical vegetations, the soot arising from mixed vitriolic oil and spirit of wine if the spirit of naphtha is made frobenianus, the Helmontian morsels, the growth of vegetables and animals, and several similar begins things teach it most clearly. The glue of bookkeepers commonly begins to putrefy contracts on the surface a wooliness or mould if it is diluted in a sufficient abundance of water and exposed. That is, the whole surface extends itself into long white filaments, often perpendicularly erect. These fibers are equal in length to 1/12 fingers and more in length in some. Within they are empty as the microscope shows, and on top they have an empty, clear globe or sphere, so that such fibers with their spheres represent a headed fungus. Several botanists believed on account of such a wooliness, which is born in putrefying bodies, that it is a peculiar species of plant born from its seed. However, I certainly persuade myself that these little fungi are born by mechanics, not by seed, through the said equivocal generation. For some say that I might see with my own eyes the rising of the fibers from the said glue. Nor in another way is it generated unless because certain fiery, volatile particles (because of their lightness about to disappear into the air, were included in a spherical membrane of glue and while it escapes with this little sphere it draws a strand with itself. This strand stiffens in this drawing out in a moment of time, and makes a steam of the new mechanical plant. However, the little sphere ascends so far until either the gravitation added to the led-forth strand, or its tenacity, impedes a higher ascension. Then the little sphere subsides and makes its head clinging to an erect strand. I have seen these plants born without seed.

LXIX.

Another thing that was decided from the water bubbles is that water in motion alone is converted not by this manner into a solid and firm body, but into an elastic body, without fire, since water will be bereft of all elasticity as long as it is a fluid.

For soapy water when first it is blown into a bubble can hardly bear without rupture the varied mutation of the figure, which, if the changing cause recedes, restores itself into the original figure. But also it has two forces, one explosive and constrictive (depending upon the oil), the other explosive and projectile and very large, arising from the water itself and not from a state of mixture, just as I have explained this phenomena more

46.

widely (47-51). For oil, because it contracts itself on the surface of the bubble and since it is flowing it cannot really be called a solid, so makes much less an elastic explosive membrane. Thus, the true solidity of a bubble is made from water, as well as its elasticity.

LXX .

Which observation is corroborated by the phenomena of Stahl especially, who makes water the author of nearly all elastic expansion in his CCC observations and here and there elsewhere in his works. For if from the fiery expansion alone of water in the inflation of air a very wise man understands this elasticity

to be analogous by no means, the faith of invention can be considered as now above I have said (11). But in truth Stahl first says that water changed in elastic inflation, the body is not made more fluid, but it has a distended form (as the expression goes) and that same distended form not by way of great heat, but also

without sensible fire is in the occupation of fermentation and much 1^-more in effervescence and in the water opposite to the salts, unrestrained it is acquired with conflict. For that same sensible sense recognizes that in these operations water is in greater bubbles visible, as smaller invisible, and it is arranged in solid membranes, which because of their solidity are made bereft of the solution, so the oily parts as the saline diminish from their interlacing, in which they were before mixed. However, new mixtures agitate all the liquid with an inner elastic motion, hence new joinings of the elements, new divisions arise. Wherefore the primary instrument of fermentation and effervescence is water, where its particles are made elastic and acquire a solid stretched form. Obviously, water acts in two ways in fermentations: first, where it is a fluid it dissolves, disperses, disjoins, mixes equally; second, where it is arranged in part in solid elastic sheets, it moves, grows warm, produces internal motion, disperses, compresses, wastes away, and coagulates.

LXXI.

And in this same phenomena of the watery membranes a new possibility of elasticity is born in the Aristotelian axiom, from the conversion of water into air. For what is air? Certainly not liquid, but the foam of liquid. Air is a clear body. If it is pure it reflects colors, of:-which it is in all ways bereft, plainly as pure watery sheets (62). Air is a compressible body -- that can be said about no other liquid, but well about the sheets of water of which a spherical body (that is, to the greatest capacity) can be changed without rupture into an oblong, narrow, irregular figure (that is, into one less full (45). Air is a body highly and eminently elastic. That again is true about no other liquid. Concerning water, however, it was shown (47-51) to acquire a similar explosive elasticity, especially its least particles cohered to themselves, and make a solid sheet. Air is a body that can have and retain for a long time an unequal surface even if it is not moved. That is, its surface is not always equal and parallel to the horizon. That again holds about no other reposing liquid, but well about the foam of liquids. For the barometers show, in diverse places and in the same place at diverse times, that the atmosphere is now higher, now lower, and a mountainous figure of clouds declares the same. Air is a body which destroys all this elasticity, and rather acquires a more constricted faculty, when phlogiston is mixed with it, as is plain through the beautiful experiments of the venerable Hales. For phlogiston brought to purer air thus is bound as if it might disappear and the

47.

sense does not discern what is made from it. Similarly, this is what is seen in the watery sheets of bubbles of which the explosive elasticity is impeded and is changed into a centripetal elastic contraction through the surrounding oily sheet (46, 49, 51). Air is a body easily broken in the form of foam and easily destroyed, and which, as it is conserved, must be generated anew daily. For it is incredible how much air at every moment of all the earth's surface is destroyed and truly consumed through the respiration of all the animals and plants, through all the effervescence and fermentations, through all the fire and flame, through all the rays of the sun. For if one might wish to make this calculation, he easily demonstrates it to be incredible the abundance of air which at every moment is thus destroyed, but nevertheless the quantity and mass of the atmosphere is preserved about the same. Whence it is necessary also that an incredible abundance of air must be generated anew daily. Whence however and from what body is it generated, if not from water, the nature of which in so many Phenomena conspires with air? And in what way is it generated from water if not that of very small particles of water, which, as long as they constitute a fluid, do not cohere

to themselves. But have an unsteady trial and they will begin to cohere to themselves and effect solid designs, of which the collection is air. These airy spherical designs are the form of bubbles. I do not determine it, nor is it necessary. For as art can make a spherical solid from water, while we form a bubble with inflation, thus perhaps nature can have other methods, changing water into elastic sheets not spherical but otherwise figured. For a spherical figure of the least airy designs can be determined because of several phenomena.

However, who ever considers all these things with doubt for them, joins the known phenomena about the generation of inflation in air greatly similar in the wind machine and other chemical operations. So it seems to be probable that the thought of Aristotle almost overcomes doubt.

At least it is easily seen that the vapor of water, since it is elastic, consists in solid sheets, and plainly it has other effects than that same water if to the same degree of heat, as they say not so much with medicine but with several mechanical phenomena.

LXXII.

The third consideration from the membrane of bubbles is born to me about

the magnitude of the smallest particles of water. The particles constituting water are small, nevertheless, they are not seen to have an incomprehensible thinness, which is attributed to them here and there in the physics books. When the 1/4 grain of lye that I

have above described is inflated through a suitable tube into a bubble, this can be extended until its diameter equals about two Rhine fingers.

If, then, you inflate another, as if you wish to repeat this bubble larger, you stretch it in vain, for soon the bubble is broken and is dispersed in every direction in particles or almost infinite to the sense atoms, as I have recounted in several places (47, 42). Whence, it is clear that such amplitude of the bubble is the greatest expansion which is possible in lye particles, for they do not bear a greater expansion without an end of continuation. When the above will have been demonstrated, this explosive quality of the bubble

48.

depends not from fat nor from the mixed in salt, but from water (50, 51). The water particles are seen to be so small, that when the diameter of the bubble equals two fingers, they cannot extend anymore. There are, however, in this lye which was used, the greater part (8/9) of water and 1/9 of soap (38, no.3), therefore, in 1/4 grain 89

of lye, from which the bubble is inflated, there are 1/9 grains of water. These 1/9 grains occupy a mass of 1/2799 cubic fingers. And they are extended in a membrane the surface of which equals 618/50 fingers squared (42). Wherefore the thickness of its membrane will be 1/17577 finger.

Therefore the thickness of this inner membrane is, obviously, 1/17577 Rhine fingers. So far in this can the water particles stretch to a certain point and cohere. If, however, the membrane is extended a little further, all water particles are separated from themselves, wherefore, this said thickness is the extreme under which the water particles can stretch themselves when they are in a state of solidity. Wherefore the least water particles (if they are spherical) will not be thicker than so 17577 of them laid down following a straight line can make the length of a Rhine finger. If, however, they are not spherical, nevertheless, one side of them will not have a greater measurement.

I understand, however, that these particles of water are in the state of solidity and elasticity. For perhaps the water particles, when changed from the state of fluidity into a state of solidity, can change their figure a little, for example from spherical into oblong, wherefore from this reckoning I considered that while obviously I have measured water particles in their state of solidity, it can not fully be concluded about the same particles in the state of fluidity. I also believe that the particles are smaller by a little than those I have determined, because the diameter of the water bubble, on which I took a measurement, is rather a little more than less from two Rhine fingers, but not enough greater, so that it can be assumed to two fingers without great error. And also, nevertheless, no hope is that one particle of water in any way ever can be seen by us through a microscope. For such a microscope is not yet invented, because the diameter of this particle is 1/17,000 fingers from other similar particles which it distinguishes perfectly accurately. Especially, however, the perfect clearness and homogenous nature of all the particles seems to permit almost that they are discerned by themselves by the sight. Since a red drop of blood from the measure of Leuwenhoeck is around 1/1000 Rhine fingers, after that the proportion between the blood drop and water can be had. Obviously in this spherical space that one drop of blood occupies, nearly 300 water particles could be contained. I refrain however from the remaining physiological consequences, which by the reason given do not flow with difficulty.

LXXIII.

By the same method also the smallest constituting parts of oils and fats can be determined. For because the outer later of the soap bubbles is oily (53-56) and of the same amplitude with the same bubble, it touches this whole thing. But, in truth, in 1/4 grain of lye, from which the bubble consists, there is not nearly 5/108 grains of fat (38, no. 3) and this outer shell does not have a thickness larger than 1/303851 fingers and in

49.

such thinness nevertheless all particles extend themselves so that a solution of continuity is not made. It follows that very small parts of fat if not smaller, nevertheless are not greater than the diameter of one particle which is 1/303851 finger. Wherefore, the diameter of one water particle to the diameter of one oil particle or fat is about 30 to 1. From which thinness shown it is understood why oils are much more penetrable than water, and they go through canals from which water is excluded.

LXXIV.

Nor does the viscous ness oppose the greater thinness which I assigned to oil particles before water, which is observed more in oils than in water. For this partly follows from the same nature of thinness, that while subtle bodies have a greater proportion of surface than thicker ones, they are more prone to cohesion; partly in truth from heterogeneous earthy and watery and salty masses which commonly cling in abundance in oils and overthrow the thickness of nose, it is rightly deduced. For pure oil set free from heterogeneous masses such as alcohol of wine and sacred oil were thickened or at least governed, But if they did not supersede the water in fluidity, nevertheless they equaled it.

LXXV.

It is certain that oil in some way for the greatest part can be truly changed into pure water, not only by the way of gentle flames burning but also if quicklime is added or another matter which draws phlogiston. They are distilled, as the common experiments of Stahl and of others clearly show. It is also certain that alcohol of wine is made from common water through fermentation, if some phlogiston is added. If therefore this is true (that from the marked thinness of oily parts before water I beheld to be able to affirm (73) ), it follows necessarily that if oil ought to be made from water, smaller particles ought to be made of it than were before. That is, so that they are worn away, divided, and made more subtle. And on the contrary if water is made from oil, or oil should return in the form of water, it will be necessary that the tiny particles are again thickened, condensed, coalesced and increased in greater masses. It is seen therefore that oil is water rubbed into least parts as if alcoholized. The instrument of this attrition and alcoholization is seen to be the motion of the prime fire, obviously of purest phlogiston approaching.

LXXVI.

Because the least water particles are by no means indivisible, or atoms, nor are they some element of the originals nor a body first and very simple, as also Aristotle disputes against Thales. For an atom or very simple and primary body cannot be divided further or worn away. But rather the least water particles are masses composed of its own kind, determined in magnitude, combined at length

from other thinner corpuscular elements, dispersed in it also. These smaller corpuscles, as they can be called in respect to the element of water, plainly necessarily have another nature than water itself, and can be the marvelous cause of phenomenon to which the physicists are accustomed to assign other matters for cause.

LXXVII.

50.

The fourth watery membrane of the bubbles has its own pores and those of a determined magnitude. Especially when it is inflated, a great part of the inflated air passes away through the pores. For if you blow violently your breath can be seen across the bubble. Therefore the bubble cannot contain or confine all the air, but part of it passes through the pores. Finally, if you fill the bubble with smoke (43) very little of this passes through the pores of the bubble but is restrained within the bubble. I considered whether the bubble and the smoke have a force for fleeing themselves by turns, and why the smoke cannot adhere strongly to the bubble, also why through the pores it cannot pass. But truly if similar outer smoke is admitted to the bubble, that is, drawn from the bubble also as from every solid body, so that on the whole surface it is moved around the bubble, as if in flickering about, nor does it flee from the bubble. Wherefore it is necessary that the particles of smoke not from the force of fleeing but because of magnitude alone are not able to transpire the pores of the bubble. Then if a clear bubble not filled with smoke thus you place so that beneath it you can put a lighted lamp, you will see a black sooty smoke from the flame of the lamp strongly surge into the bubble from the outside to penetrate and to cloud the air contained within. Therefore the pores are large enough to transmit soot. Therefore since the pores of the bubble membrane are larger than certain particles of air and than particles of oil , soot is admitted, but it is smaller than the particles of vapor born up from dry vegetables and than vapors expelled from the lungs of a healthy man in winter time.

LXXVIII.

The consideration is needed besides that a bubble is not made unless from one drop of lye, certainly from such a drop which does not fall from the tube through an

appropriate weight, and which by the variety of the tube can be now larger now smaller. For if in some tube you take in addition more of the lye than can freely ascend perpendicularly upright (however, it does not ascend higher than until the quantity entered is equal to the drop, as I assume from the observations of the most learned of Men, Muschenbroeck and Hamberger) then this superfluousness cannot be blown into the bubble, but successively it flows over the membrane of the bubble, so that it is collected beneath in a peculiar drop, hanging freely from the bubble. And also this descent of the superfluous lye is visible to the eyes, because it forms threads and flows in small rivulets. That phenomena without doubt moved Newton to believe that the matter of the bubble itself flowed and also that the top of the bubble is diminished successively.

To which is added that if a hemispheric bubble is raised over that same surface of the lye, then around the whole of the bubble on which the lye touches is a perpetual motion. For from the lye certain particles because of the force of adhesion always ascend on the solid membrane of a bubble. others descend and show some kind of circulation which is not observed if the bubble is removed from the lye. The advancing thinness of the bubble indeed ought to be made in the opinion of Newton, obviously in the constant progression in which two circles gently touching recede from the point of contact. This

51.

the autopsy wholly denies, for the black spots which arise are not successively made blacker, but have a sharp and abrupt margin, not only on the vertex, but even arise to the side, and in a bubble which has no superfluous lye, no descent of the fluid is observed unless the fat of the outer membrane. This and other phenomena I have explained in several places .

When therefore in this cohesion which the drop exerts against the tube from which it hangs, it has some relation to the magnitude of the future bubble. Especially it is seen that this test of cohesion makes a mode or measure of cohesion and solidity of all parts of the future bubble.

LXXIX.

At last from all these things which formerly were handed down about a water bubble, I conclude that the Helmont experiment about the growth of plants (and of animals too) from water is not only very true, but also the way in which such nourishment is accomplished is clear.

We formerly knew that there are two designs, from which nature arranges in every living body, namely in vessels and canals. For from these all things are composed, and by these same designs as before the diverse mixture of matter from which they are made, and various of these in conjunction with the lung here, the liver there, on that side the cerebrum and gland or flesh, here the wood and foliage of the tree, and petals of flowers or fruit and bark, and arms of polypi and the head of fungus arise. Whatever is solid in a living body, when finally we approach, is found to be always either a vessel or a canal. I make a challenge to all very wise men in search of these, that they work with various skills so that they strip off the hidden work of nature.

Whence therefore, it was shown above that some kind of grease and salt come from simple water, with the motion as external as internal. On the other hand, the vessels or solid bubbles and the canals are excited very easily. No doubt remains but that nature can make it similarly.

In the second place the prime matter from which is generated every animal and every plant, whether or not it is merely gelatin or mucilage mixed with much water?

This however is not soapy lye (as Boerhaave very correctly was wont to describe it) but namely is from water, oil, salt, and a little earth. The Origins of the solid parts of animal and vegetable bodies, particularly soft ones (for earth is abundant in bones) and before dried up (as the water which does not pertain to the solid but clings in the cavities of these is expelled), are accustomed to contain these things in almost the same proportion as in lye soap.

Nor does it oppose that the bubbles about which I spoke are much more frail and unstable than the smallest designs from which living bodies consist. For who seeks great perfection in the work of man? However, nature grows for a long time the matter and with much more intimate mixing, especially however in small working and insensible

52.

things, and the exceedingly little designs for exciting and in another method concerning the constancy. By which the smaller is the soap bubble, the longer it lasts. I blew up the bubbles through the glass capillary tube, namely the thinnest which can be had. Its diameter was around the sixth part of one line. These very small bubbles lasted to the third day in free summer air before they disappeared wherefore absolutely a much greater constancy can be expected from bubbles and canals of the smallest nature.

I am confirmed in such a thought if we consider the whole work of nutrition and how that repetition of chemicals is employed in a high degree in solution and curds, and the marvelous elastic vitality of fibers, which nothing can produce from earth, from oil alone, from salt alone, from these three mixed in any way, and several other phenomena which I omit here, since I reserve them for another occasion, when, if God will be pleased, I will publish experiments about some work in nutrition, in whatever diverse ways from all others formerly tested of the sort.

LXXX.

Formerly, with the phenomena resulting which occurred concerning the soap bubbles, I strove to demonstrate that common water is capable of various forms, especially that can be transformed into a firm and elastic body and in a certain light transaction namely with the determined motion only, especially if it contains some fat. I believe also that several physical phenomena may be explained more easily than formerly was able to be done when this continuous natural conversion of a fluid body into a solid, not of an elastic into elastic, thinner into a thicker and vice versa, is called in support. And it is haply one from the causes why in physics and medical law, motion and the mechanical doctrine was applied so often formerly (unhappily, without fruit),because only action, and not reaction, of the parts was considered. For the difference is great whether for example some globule strikes in fluid particles or solid, or the same particles which now sustain the pressure of a

fluid, either remain fluids, or with that same pressure cohere in a moment of time, are made elastic, and also change the method of reaction. For very devoted mathematicians after all applied work to explain the things, finally avoided the hidden action (in respect to mechanics), namely fermentation, effervescence, conflict of small particles, and similar ones collected.

Without which, to be sure, hardly anything in physics can be understood,

as the glorious chronicles of Borelli. Bernoulli, Keil, and of other equal men show. Wherefore, this new mechanism, as the great Leibnitz is accustomed to call the hidden mechanism, is investigated eagerly, more than formerly. Now one thing is important to me, namely the conversion of water into a very dry

body. And I spoke about the analogy of earth to soot briefly, to explain a little more accurately that which B. Stahl now shows about soot.

ABOUT THE CONVERSION OF WATER INTO SOOT

LXXXI.

Isaac Newton, in the optical considerations (query 30), says that he knows no body that is made less apt to brilliance than water. Nevertheless, if by the method of

53.

Boyle by repeated distillations it is converted into fixed earth, that earth made firm with sufficient fire is able to give off a light equal to another shining body. Some shame is suppressed at this proposition of Newton, when I think that the greatest man at his work done by night did not see the flame of his own lamp, which is nothing other than shining water -- water not yet changed into earth but joined more intimately by the fundamental principle of inflammability. Also, the great Hamberger in Physics, # 313, thinks that terrestrial particles are required for flame, because by no means can water and air glow, because of less specific gravity. Here I write with the favor of a very erudite man Manius, that he admits this latter proposition without demonstration, when rather it is certain that the degrees of heat of ignited bodies do not hold themselves in proportion to that of specific gravity, for iron (as an example) ignited glows more than ignited gold, and wood coal glows more than, if you please, ignited stone, even if the gold is found to be heavier than iron, and stone heavier than coal. On the contrary, oil and the spirit of wine, a lighter body than water, can nevertheless glow. Whence the proposition of that distinguished man without doubt is assumed out of kindness. The same learned Hamberger in Physics, # 536, in the Scholium wishing to test that for glowing cold air is always required, pulls forth pine wood which is extinguished if it is held above the hearth of a furnace. That example nevertheless proves nothing, because a wind is in the hearth; and the pine wood in such a vehement wind and great motion of air and also with the cold is extinguished. However, the same, in the wind of a furnace where the air is much hotter, burns well, and also not only temperature but the motion of the air extinguished the pine knot.

LXXXII.

I chose a hard porcelain vessel (not something less of a firm vessel which may leak of oil swimming through the cracks) and in its middle a little wick from a cotton tree I secured with the aid of perforated copper pieces. Then I poured in a sufficient portion of old and very pure olive oil. I built up the small flame with the kindled wick and as well as I could burning equally. And I knew by repeated experiences that within 15 minutes from the beginning, that is, within a quarter of an hour, through a flame of this magnitude always 25 or 26 grains of oil were consumed. For because the whole lamp with all its contents I always weighed before I kindled the wick and after the flame was put out I weighed the same lamp again, it is easily clear that I will be able to know the quantity of lost oil accurately. If I make a larger flame, not everything happens which now I tell.

LXXXIII.

I observed an opaque nucleus in the center in such a moderate flame, namely the black wick, whence I knew that the wick itself, except for a few adhering particles of soot, will not shine. Around the nucleus a globe was revealed in a sharp point above, all fire but of different color. Into this ignited globe except some peculiar little sparks I saw the splendor of the whole flame, which were brighter and more splendid than the parts of the flame remaining. These sparks appeared now more abundantly, sometimes fewer, now none. Therefore these sparks were seen to consist from other matter than the flame itself. Especially an abundance appeared if I touched and stirred the wick with an iron file. Whence I concluded that these sparks

were perhaps earth particles lying concealed in the oil or separate from the wick For the whole flame does not consist from earthy particles. I persuaded myself more firmly

54.

because I knew that oil is not without a little quantity of earth, which can by no means nourish and preserve such a flame for a long time. Especially if I thought that true alcohol of wine to be free from all mixed earth, nevertheless it was very sufficient for the nourishment of the flame.

LXXXIV.

I covered this moderate flame with a great glass funnel, thus so that on the periphery of the funnel there was sufficient space through which the air necessary for conserving the flame had free admittance. The tails of the funnel now represent a little hearth. I washed another long glass tube and placed an alembic on its summit, on which I hung a little glass in front of the vessel's beak, but without daubing with mud so that the free transit of air is withdrawn. Certainly without which the flame was suffocated. So thus I first ordered this apparatus. I saw the higher parts of the tube and the alembic with the vessel, which were before very dry, made damp with many liquid drops. Liquid thus collected I found to be very pure water, with neither a taste nor odor was I able to distinguish in it something either of salt or fat. Whence it happens that oil burning on a gentle flame is changed into water. The quantity of the water was different according to the height of the tube and of the flame. In which the less flame and more water equally, but especially in a higher tube. For if this is short, then the ascending water, not enough refrigerated, departs into the air visibly under the form of vapor through the beak of the alembic, so dispersed that it could not be captured in the vessel. I arranged my apparatus

thus several times, so that almost three parts of oil consumed under the form of very pure water I recovered. Meanwhile many sensible vapors had escaped from me under the funnel and through the joint of the vessel, whence I conclude deservedly that almost all oil, with perhaps a small portion excepted, if it burns on a slow fire, is changed into real water. Now Stahl has observed the same thing and similarly this happens with the spirit of wine, namely that in inflammation it is changed into true water. Boerhaave from others and especially Stahl describes it amply in his chemical work. Wherefore no doubt is it why flame is burning and shining water, and it is understood why bodies apt to ignition, nevertheless generate no flame if they lack dampness, as dry wood coals.

LXXXV.

If in such a flame which exhaled very pure water I placed whatever hard body you wish, for example an iron stick, so that the iron stick clearly touches the flame itself and nearly divides it, suddenly then water in the tube and alembic ceases to ascend. Rather in a moment of time a thick

copious black smoke, of which formerly no trace approached, the form of clouds through the glass tube also in the alembic, from the alembic through its beak into the vessel, and from the vessel through the cracks of the joint flies into the air. All the internal surface of the alembic and vessel and the highest part of the tube, especially the side to which the smoke greatly rushed, were colored with a very dark color, and an immoderate abundance of very dry soot is collected there. Whence I understood that from a slight cause, namely from the contact alone of the flame on some hard body, that same matter which elsewhere makes up water, is changed into very dry soot.

55.

LXXXVI.

During the kindling of the soot not a trace of water is observed to ascend from the oil. So that I might investigate that more certainly, I removed the alembic sometimes and placed a dry piece of parched clavellati ash in the glass tube. For since this salt draws water most easily, I thought for this reason to know whether it is able when a watery dampness at once ascends with soot. But this morsel of alkali salt turns out black by adhering soot. However, it remains wholly dry, unless after a space of nearly two hours, in which wearied of the labor, the iron stick removed from the contact of the flame, I restored the freedom of the flame, so that it might burn without impediment, for then quickly that salt collects some dampness. However the salt long enough removed from the flame could not be made very hot, and I add this so that one might not think that the salt drew water because of heat collected. Rather, evidently, from this it is proven that the same matter which in other circumstances gives water here constitutes soot.

LXXXVII.

Therefore, it is quite evident from these observations which are very easily repeated that for a variety of little circumstances, oil can be changed now into water, now into soot, that is, into a kind of earth. And since the same matter is made of flame, and of evaporating water and of light soot, it is permitted that the external forms differ

greatly.

LXXXVIII.

The cause of such a conversion of water into soot is marvelous in its own simplicity. For flame without impediment burning gives pure water. However, if the same is impeded in flaming through whatever hard body you wish, for example an iron stick, in its motion, the water particles binding to such a hard body and by their rotary motion suddenly ceasing are made into soot.

LXXXIX.

Nor is it necessary that that hard body which touches the flame ought

to be cold (85. For if the iron also is very hot, namely that that I made heated very brightly over the coals, and I moved it into the flame likewise, it seemed to me that a greater effect followed. Namely soot was then seen to be generated more abundantly. Wherefore that wick if it is too long, collects soot generating from water, as everyday economics teaches in practice -- that, if the candle or lamp gives off an annoying sooty smoke, the wick is cut off with forceps and thus the annoyance of smoke we are accustomed to deal with. For if the wick is too long, it divides the flame surrounding it in the same way as if an iron or other firm body had been placed in the flame, and also makes soot from the flaming water. Wherefore it happens that some soot always adheres to the side of the wick, which successively either cut short or separated with the forceps, as the candle makes more clear. And also these sooty particles hanging and flying around the wick are without doubt the cause of the diverse colors which are observed in the flame around the wick.

LXXXX.

For it does not swim for a way in the air and is lifted into such a sooty existence, but it adheres abundantly also on that same iron or hard body or wick that cuts short the flame. On the other hand on that same very heated iron put into the flame soot adheres,

56.

neither from such heat as is in burning iron is it made volatile, especially if it touches the surrounding iron. Wherefore if I place a very wide iron sheet or polished copper in place of the iron stick in the smoke, and horizontally place it thus above the flame so that the flame touches the sheet, then to that sheet in a brief space of time a quantity of soot is accustomed to collect. Never, nevertheless, even if I might use various systems, could I place the thing so that I caught all the soot born from the flame, but a great part was transmitted in the form of black clouds beyond the iron sheet, and flowed into the air with great swiftness. More often nevertheless for a brief space of time I collected such of smoke on such a sheet that more than a third part of the oil meantime consumed does it yield, thus so that when those many black clouds which pass by I count with spirit, I conclude with little difficulty that almost as much soot has ascended as of the oil was consumed. Nevertheless it was noted also that when Only through soot, the oily particles not changed were accustomed to ascend and give out a fatty soot, from which afterwards if the oily particles are separated we shall have pure soot. It is done so that if the soot of such a volatility is made wet with the best spirit of wine and is formed into small globules, and these also are exposed to a large fire in inserted twisted glasses, thus the oil is expelled and in the bottom very dry, similar to parched earthy bodies, nevertheless black, pure soot remains.

LXXXXI.

It is known from the very interesting observations of Mayov and Hales that from flame, especially when it makes soot and smoke, the air is deprived of its elasticity and is as if consumed. Therefore I thought strongly whether air forms soot to that extent that it is attracted by fire, and also not from water but from air the soot might be born. Therefore I placed my lit lamp upon a very small table in a pan full of water, and I covered it in the Hales method with a large enough inverted glass cylinder. When therefore I had stifled the commerce of the lamp with the external air, that burned not longer than 53 seconds, and in that time it consumed almost no air, after which truly it was extinguished and some black smoke was seen to emerge. The air also began to be consumed, that I knew from the ascent of water into the cylinder. I lost 1 1/2 grains of oil from all this apparatus in the time indicated, namely 53 seconds, in this closed place. Which quantity was probably converted into a watery vapor before it manifested itself in soot. However, after the flame went out then there was such a small portion of soot that it did not take measurement; meanwhile for :such a little soot brought forth through ascension 12 cubic fingers of air were freed and consumed, as I concluded from a similar mass of water drawn into the glass cylinder. However the 12 cubic fingers of air weigh about 3 grains, but this soot after the extinction of the flame issued very small and is by far beneath the quantity of one grain, wherefore by smoke the air is deprived of a certain elasticity, but it does not depart into soot. For in physical things the cause ought to be equal to the effect, because I cannot say that three grains of air consumed give forth a much smaller quantity of soot. Therefore air is deprived from elasticity by soot, but it does not constitute that same essence of soot even if the soot generated is seen to come as the necessary condition.

57.

XCII.

However, I know much more certainly that air is not changed into soot, because other burnt bodies are given which destroy air very fast and they also do not generate soot. Pure and rich coal, for instance, of smoking Celtic sod or peat does not show soot, even if it destroys a significant quantity of air in a brief space of time and deprives it from elasticity. For if I arranged a little particle of this burning Celtic peat well parched, thus so that it doesn't breathe out the least more odor and it is lacking from all the least sensible smoke, for example by the Hales method to weigh of one twenty-fourth

an ounce under an inverted glass cup, this small particle burned within 20 minutes from the first and it consumed more than 24 cubic fingers of air, namely the third part of the air in which it was enclosed, and the consumptor suddenly ceased to burn, and after it did no longer burn it also quit devouring the air, and also it was made into oil. And neither nevertheless did the peat coal emit any soot. Wherefore the air consumed in the flame is not soot, but a certain other matter, which Helmont named Gas and it is not yet well enough known. However, the peat coal did not generate soot because of the lack of water, none of which is seen in this dry inflammable body.

XCIII.

Similarly some small morsels of beech wood coal burning well, without smoke, of which the weight was not over half a drachma, enclosed in the same glass (92), were put out in a short time. Truly they consumed the air not only by the way for the long time they burned, but also after extinction, thus so that by these within 15 minutes 20 cubic fingers of air were destroyed without any sign of soot. Therefore, soot is not made from consumed air.

XCIV.

However, a tallow candle made from animal fat, plainly as the flame of the lamp from the oil of vegetables in the same glass in a short time put out, consumed the air until after its extinction. And also nevertheless the flame of the candle, also as long as the flame lasts, the process continues in free air which one can nearly see destroyed or consumed. For when a curved glass capillary tube, the diameter of the cavity of which was around 1/40 of a finger thus I applied to the glass cup, so that through it some free air could

enter the closet in the cup from the remaining air, nevertheless this tube did not detain a moment the extinction of the flame. And when another tube similarly curved, the diameter of which was 1 1/2 lines, I applied in the same way, it retarded this extinguishing of the flame for a time, nevertheless not considerably. From which separate thing it is clear that the commerce of free air is necessary for the flame, nevertheless not to generate soot.

XCV.

I understand however that the flame from the spirit of wine departs from the air into soot. For the spirit of wine burned and also under an inverted glass cup similarly burning consumes the air in the same way as the tallow candle or lamp, and also nevertheless it is very well known from the that no soot is generated from the burnt spirit of wine. From which arguments (91-95) it is clear enough that soot is born not from air, but from that same water which a little before was oil, and which is almost all water, and in truth gives up water or is changed when the flame burns without impediment. I beg

58.

pardon, however, from the readers because I have been so long in these disclosures, for this objection as to whether perhaps a dry body of soot is generated not from water but from air and particles of the atmosphere, wholly had been abridged, so that I was more certain that soot arises from that same matter which is water under other circumstances.

XCVI.

The cause of which, however, why the spirit of wine burning does not give off soot, when nevertheless it is made of a kind of very subtle oil? -- no other than because of the paucity of the element phlogiston in respect to the water, the spirit of wine flame does not heat sufficiently. For this flame is not very hot and the heat of boiling water is nearly larger, as is known from

common and economic experiences. And this heat does not suffice for water thus changed so that from it a body is made dry. I prove it by two phenomena: first, because a drop of good spirit of wine, placed in a very hot iron spoon and there burned, generates some coal or soot, see above (17,18). For after very often repeated tests this was always seen by me consistently. Second, because if some spirit of wine is added so that it can build up heat, that is changed into true and copious soot. We have an example in naphtha liquor from that very celebrated Dr. Frobian, that which once Boyle mentioned, that shows the changeable dampness in a solid body, see for example The Skeptical Chemist and, much more accurately about the same liquor, the learned I. H. Pott the chemist, writing very extraordinarily on the dispersal of wine acid. For if vitriolic oil is taken very exactly from superfluous water through exhalation, and the spirit of win4 is conducted through repeated distillations, equal portions of each are lightly mixed and then you bring near the external small heat which makes the first of the internal heat motion, this liquor composed grows very strongly heated. And immediately it establishes a very penetrating spirit of naphtha, greatly volatile. The thinness of it is significant, for the specific gravity of this liquid is my second experiment, for the specific gravity of this to alcoholized spirit of wine is very rightly and truly as 113 to 120. After which this first and on account of various causes the admirable spirit was called forth, double oil manifests itself, one of which seeks a base in the spirit, another of which floats upon the spirit and has the manifest odor of soot. Finally the matter begins to foam in the glass and thus to form expanded black bubbles, so that unless you moderate the external heat quickly, the whole mass changes in the vessel and at once a suffocating sulphuric acid vapor vehemently erupts carrying copious breath. Meanwhile, however, that which is residual in the alembic or twisted vessel is changed into a true, black, volatile ash, which if it is separated from the surrounding humid part and is moderately dried, is similar in all parts to soot, in color, odor, inflammability.

It was able to be seen that in this experiment the concurrence of an vitriolic acid material in coagulating generates soot. But truly in all the spirit of wine there is some acid through itself, but nevertheless it never generates through itself even the least bit of soot. However, in all oils which can depart into soot lies some acid, but less abundant. Whence the accession of acid alone in the spirit of wine is seen not to make soot through itself, but accidentally, namely where it increases the intrinsic heat of all the liquor.

XCVII.

Therefore soot is born when water in heat and flaming motion suddenly

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constituted is disturbed by this motion. For flame freely burning destroys water, the same suffocated by any impediment shows soot. Whence again it is clear that which I have proven above (65, 66, 67), that solid bodies do not disperse from fluids unless in a direction with a determined effort. However, water in a constituted flaming motion without doubt is hotter than the same boiling, and in this case the Amontonian rule is the necessary exception. However, this heat and flaming motion suddenly suppressed forms soot from water, thus so that water at a certain degree of heat is made flame, and in a small degree less of the heat is made soot.

XCVIII.

The dust of the soot is very thin and the smallest particles of it are not distinguished by the best microscopes. Whence it probably is that the least particle of soot is not greater than the smallest particle of water. On the other hand even smaller because the least particles of oil are smaller than the least parts of water (73) and from these as much as water soot is generated. Truly because of the blackness you can collect as you will such particles of soot which are hidden and surrounded within the fiery atoms.

XCIX.

From the soot of oils, through the spirit of wine adhering from the oil (90), was purified matter almost indestructible, with no known periodic division, except with fire. If, however, the fire built up slowly is increased, truly it releases such an abundance of terrestrial ashes as much from the oily portion from which the soot arose materially, which no one has shown to be present.

The nature of the wood coal is the same as of the soot of oils, especially when the flame of the wood is perpetually suffocated as when coals are prepared under a hill of earth in the use of metal products. For placed in a true flame they are never kindled because of the mass of the earth and because which they retain more water than the coals of kitchens which are generated by a flame, and also more hard, more nearly approaching earth and natural mineral, made less of salt and also made greatly heated they are much praised for cooking. Also from the wood which recently contained more of water is given better coals.

And it is certain that for different management of the fire from the same vegetable we are able to produce by incineration now more now less of fixed earth. That must be known when one wishes to demonstrate from wood ashes the great amount of earth which is in vegetables, because it is not yet demonstrated whether all the earth ashes lay in the vegetable before incineration. Rather, I believe that a great portion of the earth present should be generated in the fire. For who can show earth in a coal before it is incinerated?

This Newman sometimes noted in his chemical commentaries, namely that with a vegetable of the same goodness, by its diverse treatment it gave a different abundance

60.

of insoluble earth. And also it was known from coals which are prepared under a hill of earth suffocated by fire that they exhibit no alkaline salt, whence these coals of wood, which are prepared under the hearth in free air from green wood especially. A sign of alkaline salt or an abundance of little ashes is manifest. Wherefore in such a suffocated fire this is earth itself that is made an alkaline salt in free air. However, we know that salt and earth do not differ unless by the reason of a greater proximity with water. For salt (by the teaching of Stahl) is water peculiarly modified. However, it is evident that earth is made from salt. From culinary salt is generated true sand if phlogiston is connected with air for a long time, which economics observed in meats and fishes kept in salt brine for a long time. But now it is also known by physicists. It can be read in the Commercium Litterarium of Nuremberg. Wherefore this is a new passage of water into earth while salt from water first, from which finally earth is produced.

CI.

We have therefore two new methods which nature uses for generating solid bodies from water. The first namely if water connects with phlogiston to form oil, finally when it changes this oil into a firm sooty body. Thus are seen to be born the pollen of plants, sulphur, seeds, and other bodies, thus the fresh sulphur from mineral and perhaps certain metal. Nor ought we to object that such heat is not in plants as much as the flame in a lamp. For thus it is argued that nature does not draw attention to produce its work, in a motion most perfect and insensible. And the solar rays which are collected through a

convex glass induce just such a stupendous heat in a moment of time. And they are thus often concentrated on a point in various other ways by nature and bent inwards so that by man such force is not possibly to be imitated. We have an example in the attrition of bodies, so that if steel is rubbed with a stone, immediately there is electricity. However, there is another method, when nature through the accession of the principle of fire forms salt from water first and finally this gently goes into the form of earth. Of this natural conversion therefore an artificial method can be shown with prepared glass. For it was parched glass from which was made a kind of very hard soap, consisting from fused liquid earth, and alkaline salt, and phlogiston drawn by fire. This fixed lye blown by work into bubbles forms a new extension of earth, namely a kind of glass, from which water bubbles hardly differ unless with a lesser fragility.

CII.

And these things are less incredible since in other bodies we have such a frequent similar conversion, and the repetition of ancient chemistry wherever you wish with liquid and solid is provided by nature. Truly the instrument of solution and coagulation and several others is fiery motion applied with a diverse degree. For example, it is known that lead is a solid body in the heat of our atmosphere, that it liquefies in a medium fire, and that it is a hard body again in a little stronger degree of heat, namely as calx of lead. Finally it is changed into rust of lead and semi-vitreous lithargyrium. Thus the same solid

61.

rust of lead is commuted into a new flow in a kind of fluid glass if the degree of the fire is again augmented. And thus next, as in lead, various manner and degree of fluidity and firmness are thickened with varying heat. Similarly this agrees with the observations of

Glauber and Homberg on mercury, especially however from the long labor of Boerhaave, that it is a fluid but always fixed in the heat of the atmosphere. With added heat it transformed exhales vapors. However with continued and more intense heat it is commuted by fire alone into a solid body full of dust. This dust, if again the fire is intensified, is again partly made fluid. Another part is made truly more solid and more fixed, so that it withstands great fire. It, nevertheless, finally at the degree of fire which is in the glass of flowing lead, liquefies again and flies apart. We have described that with admiration from the most noted experiments of Boerhaave on mercury. From this and other examples I conclude that it is not improbable that both water which is hard ice in the winter time and liquefies in the greater summer heat, with increased heat can once more depart into a dry body and one strongly terrestrial. Whence the conversion of water into earth is seen to be especially encouraged by the instrument of fire.

However, I think that now it must be refrained from, not that I began to write in a certain place, but at last interrupted and uncertain, I have no experiments to add by which I might explain the nature of water, at least none singular from those which I have already described. When, however, they were imperfect, I removed them for a scrupulous reason. I shall retain them until I become more certain. This little bit, however, take, benevolent reader, nor scorn them.-because they are based on water, a most noteworthy body. For the use of water lies widely not only in the living bodies of this kingdom, since without water there is no bodily life, but also in the whole mineral kingdom. Water was referred to as the first miracle of creation and because of its own simplicity and sufficiency it especially leads us to the knowledge and veneration of God, the eagerly desired and most beautiful End of all knowledge.

A VIEW OF THE WHOLE WORK

First Part

In which are recounted briefly the excellent teaching, of old and more recent about water.

I. The phenomena of simple bodies teaches the intellect more than those of compositions.

II. In knowing water all sciences are used. Physics and Chemistry formerly little about water changes for sure.

III. Certain phenomena of water were known by all men

IV. Water was once represented among the elements because of its simplicity. The Aristotelian hypothesis about the element is praised.

V. The Aristotelian principle is explained, and the qualities of his primary bodies in recent; and everyday terms are explained. At the same time it is inquired concerning the absolute lightness of fire inrespect to the center ofthe earth. The -necessity of

62.

this inquisition is indicated, that ifthe light fire absolutely is a false rule, the masses are proportional to the specific gravity.

VI. There are problems of primary bodies in their conversions.

V11 . The experiments of antiquity are reviewed as to whether water can be changed into air.

VIII. And the objections against the change of Guericke, Boyle,de la Hire.

IX. Water vapors are as elastic as air.

X. When water itself is made least elastic.

XI. Stahl the inventor loves to speak of the elasticity of water. In what sense it was true.

XII . The contrivance of Amontonius always equals the heat of boiling water.

XIII . About the method and abundance of the exhalations of water.

XIV.The problem is whether water can be converted into fixed earth.

Second Part
It contains observations about the different fixation of water in

different degrees of heat.

XV. Water in heat which is greater than is required for boiling is fixed, and the more fixed the greater is the degree of heat in it, which is shown with new experiments, especially in the heat of burning iron.

XVI. Each phenomena is again considered.

XVII. In what manner the spirit of wine, behaves it self in the heat of glowing iron.

XVIII.In such heat water gives up fixred earth ,and the spirit of wine gives up soot.

XIX. A new method and the most certain of all for examining the goodness alcohol.

XX. In what manner the spirit of sal-ammoniac behaves itself in the heat of glowing iron.

XXI. And the oil of olives.

XXII. That in such heat the air which is in water is fixed in proportion also.

XXIII No liquids are made fixed in such heat except simple water and air.

XIV. Water is displayed in such heat, not, because of the absence
of an atmosphere but from the action of the fire itself, to be made more fixed.

XXV. Whence a new thermometer is proposed for measuring large

degrees of fire, which by an ordinary thermometer cannot be measured.

XXVI. The use of this thermometer is taught by a certain example. Water in the heat of glowing, iron is three times more fixed than quicksilver.

XXVII. Water in heat which is greater than of iron is again more volatile and highly elastic.

XXVIII. Earth glowing in fire is not much more hot than boiling water, wherefore it is never melted. Scores of iron similarly. The highest heat in the fire is of melted salts.

XXIX. Water in the heat of glowing iron is not hotter even if it is more fixed.

XXX, XXXI. Whether part of water through the heat of glowing iron is changed into fixed earth.

63.

XXXII. A transition is made to the following: whether water in a firm body is changeable, unless they are the existence of ice in the first two experiments tried, one of Boyle, the other of Helmont.

XXXIII. The experiment of Boyle is confirmed.

XXXIV. The objection of Woodward is indicated against the Helmont experiment.

XXXV. And it is refuted.

THIRD PART.

About the solid state of water, when bubbles are made from it.

XXXVI. What a bubble is, and from what it is made.

XXXVII. On soap and its varieties.

XXXVIII. About the nature and constitution of the black soap of Holland certain things are taught, because of it in concourse large and very beautiful bubbles are made.

XXXIX. In what manner a bubble is made.

XL. In what manner the phenomena of bubbles can best be inspected.

XLI. The magnitude of bubbles varies for the magnitude of the drop from which it is inflated.

XLII. The thickness of the membrane of all bubbles is at least 1/15624 of a Rhine finger.

XLIII. The membrane of a bubble is a solid body, which is proven by various phenomena. In what manner smoke is contained in a bubble.

XLIV. The same membrane is not humid but dry.

XLV. And very elastic.

XLVI. A bubble at first has a force and struggle f contracting itself, as long As it is flexible.

XLVII. Finally it is rigid and endures the force and explosive struggle, so that its particles sudden1y and widely are dispersed from itself in turn.

XLVIII. A bubble in the same way splits into dust as the tail of a glass tear is broken.

XLIX. Therefore a bubble has a double force opposing itself, namely centripetal and centrifugal.

L. In which the more saturated is the lye soap from which the bubble is formed, the greater is the centripetal force in it. In which the more diluted is the lye, the greater is the centrifugal force in it.

LI. The centripetal force of the bubble depends upon oil.

LII. In the membrane of the bubble, oil and water are obviously separated which were quite mixed before in the lye. From this is the origin of colors.

LIII. The membrane of a colored bubble consists of three layers. The exterior colored one oily; the middle white one salty; the inner clear or very black one is watery.

LIV. The outer layer of the bubble is proven to be oily from phenomena.

LV. This outer layer does not c1incg to the interior ones unless loosely, and is able to be moved variously over the immovable interior ones. This one only generates colors.

LVI. That it appears clearer to the naked eye if the membrane of the bubble is made not spherical but plane.

64.

LVII. If the lye is well mixed, that is, so that the oily parts cannot easily secede from the watery ones, then the bubble never assembles colors. Wherefore the bubble from the saliva. of a healthy man has no colors.

LVIII. Similarly from urine, and from other well mixed liquids.

LIX. Wherefore in a colder atmosphere the colors appear -more distinct.

LX: LXI. The Newtonian colors are not reflected from the whole membrane of the bubble, but from the exterior sheet of it, by the reckoning of Newton himself it is demonstrated.

LXII. Pure water lacking all oil never reflects colors, wherefore the

doctrine of Newton about the colors of the thin sheets must be limited here. But the various refraction of colors in water is proven by the different colors of ice.

LXIII. The truth of these observations is asserted.

LXIV. Therefore water through inflation alone can be changed into a firm, membranous body.

LXV. The true difference which intercedes between a fluid body and a firm one.

LXV I. About the plaited thread of spiders,which in a moment of moment of time solidifies.

LXVII. Next the difference of fluids and of solids is explained, that in the test it is melted with the difference only of the particles.

LXVIII. The cause which makes a solid from a fluid is bounded motion. This cause is either in an intrinsic fluid, or outside that, extrinsic. About the generation of plants without equivalent seed.

LXIX. Water is the basis of elasticity in the membrane of a bubble.

LXX. And the assertion of Stahl about the elasticity of water is affirmed and explained.

LXXI. That air is generated from water is made probable by new arguments.

LXXII. From the measure of the bubble i s proven that one particle of water has a diameter or 1/17577 of a Rhine finger. Wherefore in one Leuwenhoekian globule of blood can be contained nearly 300 water particles.

LXXIII. The diameter of the least oil particle is to the diameter of a globule as 1 to 30.

LXIV. That is defended against an objection.

LXXV. Oil is seen to be water in its least particles broken and wasted by fermentation.

LXVI. Wherefore water is not an element.

LXXVII. The water membrane of the bubble has pores of a certain and determined magnitude.

LXXVIII. The adhesion of the drop to the tube from which it is inflated is the measure of solidity in the same membrane of the bubble.

LXXIX. All animals and all plants consist from two designs joined in various orders to themselves, namely tube and vessel. And the matter of them is lye soap. Wherefore Helmont rightly judged all plants to grow from water ( to which one ought to add some salt and fat).

LXXX. The usefulness of this doctrine is indicated in physical and medical theory.

Fourth Part

Of the conversion of water into ash.

65.

LXXXI. Water can burn and glow also when it is not yet turned into earth.

LXXXIII. LXXXIII. Certain phenomena of flame are shown from oil.

LXXXIV. The moderate and undisturbed flame of oil is all changed into purest water.

LXXXV. The same flame disturbed is all converted not into water but into soot,

LXXXVI. During the ascension of soot no sign of water exha1es from the oil. That in a singular experiment is taught.

LXXXVII. Water and soot are the same matter.

LXXXVIII. And the cause of such mutation is its own marvellous simplicity, indeed the attraction alone of a hard body.

LXXXIX. Heat or cold of this hard body is indifferent by reason of the generation of soot.

XC. Soot ascending adheres to hard bodies easily, and also can so be collected.

XCI. It is inquired whether soot is generated from air rather than from water, and it is denied from phenomena.

XCII. Batavian peat glowing destroys air, nevertheless it does not generate soot.

XCIII. Wood coal glowing destroys air, nor does it generate soot.

XCIV. Tallow grease glowing destroys air, nevertheless in that time it does not make soot.

XCV. The spirit of wine burnt consumes much air nevertheless it does not put forth any soot.

XCVI. The spirit of wine is changed into soot if a greater degree of heat is acquired by it.

XCVII. Soot is water of of which the flaming motion is suddenly suppressed, surrounded with fiery particles.

XCVIII. The least particles of soot are seen not to be greater than the least particles of water.

XCIX. Soot is a matter indissoluble by common measures, with the exception of fire. This treatment yields much earth.

C. The nature of wood coal is almost the same as soot. Coal is not earth.

CI. From water into earth is a double transition, the first when it is changed into oil, the other when it is changed into salt.

CII. The conversions of this type of solids into fluids and vice versa also in other bodies are familiar by a different degree of fire applied, such as in lead and mercury.

The End.

Set to type by Joan. Sebast. Straube, typographer to the Academy.