ALCHEMY, an occult science, which pretended, by means of a sublimer chemistry, to teach modes of form ing the philosopher's stone, the universal medicine, and the universal solvent; and of producing the precious metals and gems from common and cheap materials. The term alchemy, however, has been usually employ ed in a more limited sense, to denote the art of forming the philosopher's stone, and, by means of it, transmuting the inferior metals into gold and silver. This subject derives considerable interest from the strange delusion with which it misled philosophers for a period of more than one thousand years; from the effects of that delu sion upon the happiness of society during its reign ; and from the powerful influence which it has had upon the progress of science. We shall on these accounts con sider it more fully than, from its intrinsic merit, the sub ject deserves.
The ancient philosophers conceived the various bo dies in moire to he composed of four elements, viz. earth, water, air, and fire. (See .ETHER,) Of these philosophers, the atomists, who had by far the most cor rect views of physical science, held, that each body derived its peculiar properties from the proportion of the elements which entered into its composition, and the mode in which they were combined. By elements, how ever, they did not, as in modern chemistry, 111Call pri mary principles, which no operation of nature or art is capable of changing ; for they believed that the different elements were mutually convertible. Thus Ileraclitus says, vetpo; .9.6vX•r5; /evicts And again, :Oc4.71 &r...0i7o570 yeveTtlict that is, the death of fire is generation to air, and the death of air is genera tion to water : and it is death to water to become earth. By this hypothesis, these philosophers explained several of the appearances in nature. They did not attempt. however, to make toly application of this theory to the arts ; a neglect which seems to have arisen front the cir cumstance, that. as the manual arts were then practised chiefly by slaves, men of liberal education considered any attention to them as a degradation of their character. But w hen, by the universal diffusion of Christianity, slavery was abolished, and the arts were cultivated by free men, these prejudices were gradually removed, and philosophers no longer disdained to engage in manual operations, either for instruction or for profit. They soon perceived that it followed as a necessary conse quence, from the theories of their predecessors, that any substance in nature may be changed into any other, either by adding to it or subtracting from it, a portion of certain elements, or by transmuting some of those ele ments which it contains into different ones. The science of chemistry, which treats of the changes produced in bodies by different agents, held out the prospect of ena bling them to effectuate such permutations, and some of its results were adapted, in that state of science, to flatter them with the idea of having actually changed a small portion of the inferior metals into gold or silver. Lead and copper are frequently alloyed with these valuable metals. Consequently, when the former are subjected to the operation of powerful chemical agents, the latter, which do not so easily put off the metallic aspect, would sometimes become apparent in the residuum. Such a
result would naturally give rise to a belief, that these metals had been actually formed during the operation, and would lead the artist to imagine, that by varying the process he could procure them in greater quantity. These are probably the particular circumstances from which alchemy had its origin ; but the early history of this delusion is involved in too much obscurity to ena ble us to form a decided opinion.
The alchemists pretend that Noah was acquainted with this art. It is even shrewdly suspected by these gentlemen, that Adam had considerable knowledge of the subject. After the death of Noah, his descendants carried with them this science into the different regions of the earth over which they were dispersed. Some of these colonies, however, gradually sunk into ignor ance, while others cultivated the different parts of know ledge with considerable success. The most celebrated of the ancient nations, for their acquisitions in science, were the Egyptians ; among whom Hermes Trismegis tus, at a very early period, is alleged to have been a great master in alchemy, and to have inscribed his dis coveries upon stone pillars. These discoveries were al so preserved by the Egyptian priests, in hieroglyphic characters, upon the walls of their temples, and in writ ten books, which they kept particularly secret. The Egyptians were supposed to have communicated this knowledge to Pythagoras and several other Grecian philosophers, after many years anxious attendance and earnest solicitation. This account of the origin of al on forced interpretations and spurious works of A.elent authors, is when:y unworthy of credit. Thu first certain notices which we have of the existence of alchemy are referable to the third or fourth century, about w inch dine it appears to have heen pursued with considerable ardour oy the Greek ecclesiastics, whose treatises upon tne subject arc numerous, though little valued by their successors. At this period the attention of alchemists seems to have been chiefly turned towards the lormation of silver and gold. in consequence of the Mahometan conquests, alchemy was transferred from the Greeks to the AI abians ; and, by this change, became more extensive in its signification, as well as more en couraged by the patronage of the great. The Arabian physicians introduced into medicine the use of mercurial preparations, and were led, by the success of this first experiment, to form very presumptuous hopes of the power of chemical substances in curing disease. Al chemy was then no longer confined to the transmutation of metals, but included an art not less interesting to the human mind,—that of preparing an universal medicine, which should be a remedy for all diseases, and the means of protracting indefinitely the life of man. Thus ad dressing itself to two of the most powerful principles of our nature, the desire of riches and longevity, this delu sion extended its fascination to every rank in society. It was patronized by the rich, and eagerly prosecuted by the learned. The illustrious names of Gebel-, Rha zes, and Avicenna, appear, in the number of its votaries.