We have already mentioned, that the belief in alchemy probably had its rise from an application of the atomic theory to the phenomena of chemistry. But from the obscure style of alchemical authors, it is impossible to trace a distinct theory in most of their writings, or to find a consistency in their ideas. Some of these writers indulge in the reveries of the Platonists ; others arc deeply infected with the delusion of celestial influences, and a thousand other ridiculous fancies. It will there fore be sufficient to mention the theory, which has been avowed by the latest and most intelligent of the alche mists. They supposed the metals to be composed of two substances, metallic earth, and an inflammable prin ciple, which they called sulphur. In gold, these prin ciples were found nearly pure ; but, in the other metals, they were contaminated with different foreign ingre dients, by being purified from which, they would be con verted into gold. To this purification, their various processes had a reference. Among the earliest of the alchemists, who held this theory, neither the earth, nor sulphur of metals, seem to have been considered as sim ple elements ; but the later alchemists appear to have viewed them in that light. The great instrument by which the purification of the metals was to be produced, they called,—the philosopher's stone, the lapis tingcns, the medicina metallorum, the elixir, the powder of pro jections, &c. A small portion of this substance, by be ing projected into any of the inferior metals, while in fusion, would convert the whole mass into gold or sil ver. The opinions, concerning the operation of the philosopher's stone, were various. Some conceived it to act as a ferment upon the inferior metals ; others as a corrosive, which consumed their impurities ; and a third set seem to have conceived its action somewhat similar to that of lead, in refining the superior metals. The
first alchemists believed in only one species of philoso pher's stone ; but the inconsistencies of different au thors, in treating of its powers, rendered it necessary for their successors to believe, that this stone differed in the quantity of metal, which a given weight of it was capable of converting into gold ; thus, when formed ac cording to one process, an ounce of the stone could con vert only ten ounces of lead or copper into gold ; but, if formed according to another process, it was capable of transmuting one thousand times its own weight. Basil Valentine makes a farther distinction between different stones ; besides the lapis fihilosophorum, or philosopher's stone, which is formed from gold, and converts all metals into that substance, he supposes several other stones, which are only capable of transmuting particular metals ; " sed lafiis iglus," says he, " not tingit universaliter, sicut lapis fibilosopborum gui ex sobs essentia paratur : neguaguanz. Etenim tantum ei concessum non est, ad ef ,ficiendum Rua vitiate, verum tingit particulariter, nempe lunam in solem pr.eter stannum et plumbum : Marten et Venerem equidem All the adepts agree that the colour of the philosopher's stone was red ; but differ very much concerning the substances, from which it may be formed. In consequence of this diversity of opinion, it has been sought for in innumerable bodies, some of them the most execrable, and by processes extremely tedious and pernicious to the health of the operator. See An drew's History ; vol. ii. p. 87. ; Pontanus and Hamel ; Irene us Phdaletlia ; Price's pamphlet, entitled, dlecounta from Erptriments performed at Guilford. A. C.