ELEMENTS
OF THE
THEORY AND PRACTICE
OF
CHYMISTRY·
Translated from the French of
M. MACQUER,
Member of the Royal Academy of Sciences, and Professor
of Medicine in the University of Paris.
The FIFTH EDITION.
EDINBURGH:
Printed for Alexander Donaldson; and sold at his Shop, No. 48, East Corner of St. Paul's Church-Yard, London; and at Edinburgh.
M. DCC. LXXVII.
THE
AUTHOR's
PREFACE.
An hundred and fifty years are scarce elapsed since the clouds of prejudice, which had long overspread the world, began to clear up, and men were convinced, by cultivating the Sciences, and attending to Nature, that no fanciful hypotheses would ever lead them to the true causes of those various phenomena that incessantly and every where meet the observer's eye; but that the narrow limits of the human understanding confine the course of our researches to one single path; namely, that of Experiment, or the Use of our Senses. Yet, in this short period, Natural Philosophy hath risen to a high pitch of improvement, and may with truth be said to have made much greater advances towards perfection, since the experimental method was introduced, than in the many ages before.
This is true with regard to every branch of Natural Philosophy; but more particularly with regard to Chymistry. Though this Science cannot be said to have ever existed without experiments, yet it laboured under the same disadvantages with the rest; because those who studied it made all their experiments with a view to confirm their own Hypotheses, and in consequence of principles which had no foundation whatever, but in their wild imaginations.
Hence arose that enormous heap, that incongruous jumble of facts, which some time ago constituted all the knowledge of Chymists. Most of them, and especially those who assumed the pompous title of Alchymists, were persuaded that all the Metals were no other than Nature's rude unfinished essays towards making Gold; which, by means of due coction in the bowels of the earth, advanced gradually towards maturity, till at last they were perfectly converted into that beautiful and precious Metal.
On this principle, which, if not demonstrably false, is at least utterly destitute of proof, and unsupported by a single observation, they attempted to finish what Nature had begun, by procuring to the imperfect Metals this much desired coction. To attain it they made an infinite number of experiments and trials; which all conspired to detect the falsity of their system, and to satisfy men of sense, that the methods they employed were very far from answering the purpose.
However, as facts always promote the knowledge of Nature, it happened that those experiments, though quite useless with regard to the end for which they were originally made, proved the occasion of several curious discoveries.
These lucky consequences of their mistaken labours raised the courage of the Chymists, or rather Alchymists, who looked upon every such instance of success as a new step towards the Grand Work, and greatly increased the fond opinion they entertained of themselves, and of their Art, which, on that account, they set up very high above all other Sciences. Nay, they carried this notion of superiority so far, as to hold the rest of mankind unworthy, or incapable, of rising to such sublime knowledge. In consequence thereof Chymistry became an occult and mysterious Science; its expressions were all tropes and figures, its phrases metaphorical, and its axioms so many enigmas: in short, an obscure unintelligible jargon is the justest character of the Alchymistic Language.
Thus, by endeavouring to conceal their secrets, those gentlemen rendered their Art useless to mankind, and brought it into deserved contempt. But at length the genius of true philosophy prevailed in Chymistry, as well as in the other Sciences. Some great men arose, who had generosity enough to think their knowledge no otherways valuable than as it proved of service to Society. They did their utmost to introduce both the knowledge and the practice of many important secrets, till then of no use; they drew aside the veil which hid the charms of Chymistry; and that Science emerging from the profound obscurity, in which it had for many ages lain concealed, gained the admiration of the world as soon as it appeared in open day. Several societies of ingenious men were formed in the most learned countries of Europe, who vied with one another in their labours to execute the noble scheme, and assisted each other by mutually communicating their discoveries. Chymistry made the most rapid progress, enriching and perfecting the Arts derived from, or depending on it. In a word, it put on a new face, and became truly worthy of the title of Science; founding its principles and its processes on solid experiments, and on just consequences deduced from them.
Since that time the Art is become so extensive, by the numerous discoveries which Chymists have already made, and are daily making, that large volumes are required to contain a complete Treatise on the subject. In short, Chymistry may now, in some degree, be compared to Geometry: each of these Sciences takes in a most ample field of inquiry, which every day enlarges very considerably; from each are derived several Arts, not only useful but even necessary to Society; each hath its Axioms and its undeniable principles, either demonstrated from internal evidence, or founded on constant experience; so that the one, as well as the other, may be reduced to certain fundamental truths, on which all the rest are built. These fundamental truths connected together, and laid down with order and precision, form what we call the Elements of a Science. It is well known that there are many such works relating to Geometry, but it is not so with regard to Chymistry; there being very few books which treat of this Science in an Elementary manner.
Yet it must be owned, that performances of this kind are exceedingly useful. Many who have a relish for the Sciences, but have not leisure to read elaborate Works which treat of them minutely, are glad to meet with a book from which, without sacrificing too much of their time, or neglecting their ordinary business, they may obtain a taste or just notion of a Science that is not their principal study. Those who incline to go farther, and learn more, may, by reading an elementary tract, be enabled to understand Authors, who, as they commonly write only for proficients in the Art, are obscure and hardly intelligible to mere beginners. Nay, I presume to say, that an Elementary Treatise of Chymistry may prove a very useful book, even to those who have made some progress in the Science: for as it contains only the fundamental propositions, and indeed is an abstract of the whole Art, it may help them to recollect the most important parts of what they have read in many different works, and fix in their memoirs the most essential truths, which might else be either confounded with others, or entirely forgot. And these are the motives which determined me to compose the Work which I now offer to the Public.
The general Plan on which I proceed is to suppose my Reader an absolute Novice in Chymistry; to lead him from the most simple truths, and such as imply the lowest degree of knowledge, to such as are more complex, and require a greater acquaintance with Nature. This order, which I have laid down for my rule, hath obliged me to begin with examining the most simple substances that we know, and which we consider as the elements whereof others are composed; as, by knowing the properties of these elementary parts, we are naturally led to those of their several combinations; and, on the other hand, in order to know the properties of compound bodies, it is necessary we should be first acquainted with the properties of their principles. The same reason induced me, when enquiring into the properties of one substance, to take no notice of those which relate to any other substance not treated of before. For example: as I treat of Acids before Metals, I say nothing under the head of those Acids concerning their power of dissolving metals; that I defer till I come to the subject of Metals: and thus I avoid speaking prematurely of a substance with which I suppose my Reader wholly unacquainted. And this method I was so much the more easily induced to follow, that I know of no Chymical book written on the same Plan.
After discoursing of Elements in general, I treat next of such substances as are immediately composed of them, and are, next to them, the most simple: such are all saline substances. This head comprehends mineral Acids, fixed Alkalis, and their several combinations; the volatile sulphureous spirit, sulphur, phosphorus, and the Neutral salts which have an earth or fixed Alkali for their basis: those which have for their basis either a volatile Alkali, or some metallic substance, are referred, according to my general Plan, to the heads under which I treat of those substances.
Metallic substances are scarcely more compounded than the saline; which induces me to consider them next. I begin with those which are the most simple, or at least seem to be so; because their principles, being very strongly connected together, are separated with the greatest difficulty: such are the Metals properly so called; namely, Gold, Silver, Copper, Iron, Tin, and Lead. After these come the Semi-metals in order; to wit, Regulus of Antimony, Zinc, Bismuth, and Regulus of Arsenic. Mercury being a doubtful substance, which some Chymists rank with the Metals, and others with the Semi-metals, because it actually possesses certain properties in common with each, I have treated of it in a separate Chapter, which stands between the Metals and Semi-metals.
I next proceed to examine the several sorts of Oils, whether Vegetable, which are divided into fat, essential, and empyreumatic; or Animal, and Mineral Oils.
By examining these substances we obtain ideas of all the principles which enter into the composition of Vegetable and Animal bodies; that is, of those substances that are capable of fermentation: this enables me to treat of fermentation in general; of its three different degrees or kinds, the spirituous, acetous, and putrid; and of the products of those fermentations, ardent spirits, acids analogous to those of vegetables and animals, and volatile alkalis.
The order in which I treat of all those substances being different from that in which they are obtained from compound bodies, I give, in a distinct Chapter, a general idea of Chymical Decomposition, with a view to shew the order in which they are separated, from the several bodies in the composition whereof they are found. This brings them a second time under review, and gives me an opportunity of distinguishing those which exist naturally in compound bodies, from those which are only the result of a new combination of some of their principles produced by the fire.
The succeeding Chapter explains the late Mr Geoffroy's Table of Affinities; which I take to be of great use at the end of an Elementary tract like this, as it collects into one point of view the most essential and fundamental doctrines which are dispersed through the work.
I conclude with an account of the Construction of such Vessels and Furnaces as are usually employed in Chymistry.
In this Part I say nothing of any manual operations, or the several ways of performing Chymical processes; reserving these particulars for my Treatise of Practical Chymistry, to which this must be considered as an Introduction.