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 hisShop, No. 48, East Corner of St. Paul's Church-Yard,London; and at Edinburgh.
M. DCC. LXXVII.
An hundred and fifty years are scarce elapsedsince the clouds of prejudice, which had longoverspread the world, began to clear up, and menwere convinced, by cultivating the Sciences, and attendingto Nature, that no fanciful hypotheses wouldever lead them to the true causes of those variousphenomena that incessantly and every where meetthe observer's eye; but that the narrow limits of thehuman understanding confine the course of our researchesto one single path; namely, that of Experiment,or the Use of our Senses. Yet, in thisshort period, Natural Philosophy hath risen to a highpitch of improvement, and may with truth be said tohave 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 NaturalPhilosophy; but more particularly with regard toChymistry. Though this Science cannot be said tohave ever existed without experiments, yet it labouredunder the same disadvantages with the rest; becausethose who studied it made all their experimentswith a view to confirm their own Hypotheses, andin consequence of principles which had no foundationwhatever, but in their wild imaginations.
Hence arose that enormous heap, that incongruousjumble of facts, which some time ago constitutedall the knowledge of Chymists. Most of them,[Pg iv]and especially those who assumed the pompous title ofAlchymists, were persuaded that all the Metals wereno other than Nature's rude unfinished essays towardsmaking Gold; which, by means of due coction inthe bowels of the earth, advanced gradually towardsmaturity, till at last they were perfectly convertedinto that beautiful and precious Metal.
On this principle, which, if not demonstrably false,is at least utterly destitute of proof, and unsupportedby a single observation, they attempted to finish whatNature had begun, by procuring to the imperfectMetals this much desired coction. To attain it theymade 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 methodsthey employed were very far from answering thepurpose.
However, as facts always promote the knowledgeof Nature, it happened that those experiments, thoughquite useless with regard to the end for which theywere originally made, proved the occasion of severalcurious discoveries.
These lucky consequences of their mistaken laboursraised the courage of the Chymists, or ratherAlchymists, who looked upon every such instance ofsuccess as a new step towards the Grand Work, andgreatly increased the fond opinion they entertained ofthemselves, 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 tohold the rest of mankind unworthy, or incapable, ofrising to such sublime knowledge. In consequencethereof Chymistry became an occult and mysteriousScience; its expr