The alchymists laid it down as a first principle, that all the metals arc composed of the same ingredients .
rather they affirmed, that the principles which compose gold exist in all the metals, contaminated indeed with various impurities, but capable, by a proper purification, of being brought to its perfect state. The great object, therefore, of their researches, was to find out the means of producing this purification, and consequently of con verting the baser metals into gold. The substance which possesses this wonderful property they called lapis philo sophorunz, or the philosopher's stone. And many of them boasted, that they were in possession of this grand instru ment.
Chemistry, as the term was used by the alchymists, was the art of making the philosopher's stone. They affirmed, that this art was above the reach of the human capacity; and that it was made known by God to those happy sages only whom he peculiarly- favoured. fortunate few who were acquainted with the philosophers' stone called themselves at/dal, adepts, that is, persons who had got possession of the secret. This secret, they pretended, they were not at liberty to reveal, affirming that dire misfortune would fall upon that man's head who ventured to disclose it to any of the sons of men, without the clearest tokens of the divine authority.
The alchymists, in consequence of these notions, made it a rule to keep themselves as private as possible. They concealed, with the greatest care, their opinions, their knowledge, and their pursuits. And in their communi cations with each other, they adopted a mystical and metaphorical stile, and employed peculiar figures and signs, that their writings might be understood by the adepts only, and might be entirely unintelligible to com mon readers.
Notwithstanding all these obstacles, a great number of alchymistical books made their appearance during the dark ages ; many of them under the real names of the authors, but a still greater number under feigned titles, or ascribed to the celebrated sages of antiquity. Though,
during the whole of this period, the art of printing was unknown, and books consequently were multiplied with great labour and expence, this does not seem to have much lessened the number of alchymistical tracts. They must, therefore, have been bought up with eagerness, even by those who had no pretensions to the title of adepts ; but who were buoyed up by the delusive hopes of becoming masters of the grand secret, and of suddenly rising by its assistance to affluence and distinction.
flow far the alchymistical sect had extended among the ancients, or whether it had assumed the form of a sect, it is impossible to say. Traces of it appear among the Arabians, who turned their attention to literature soon after the conquest of the caliphs, and who com municated to our barbarous ancestors the sacred seeds of science. The principal chemical writers among the Arabians were Gebel. and Avicenna ; and in their writ ings, such of them at least as we have reason to con sider as authentic, there appears but little of that mysti cism and enigma which afterwards assumed a systematic forms.
The alchymists seem to have been established in the west of Europe at least as early as the 8th century. Between the 11 th and 15th centuries, alchymy was in its most flourishing state. The writers who appeared during that period were sufficiently numerous, and vary different from each other, both in their style and abilities. Some of their writings are totally unintelligible, and bear a stronger resemblance to the reveries of madmen, than to the sober investigations of philosophers. Others, if you make allowance for their metaphorical style, are written with comparative plainness, display considerable acuteness, and indicate a pretty extensive acquaintance with natural objects. They often reason with great accuracy, though generally from mistaken principles ; and it is not unfrequently easy enough to see the ac curacy of their experiment, and even to point out the particular circumstance which led to their wrong con elusions.