Little is known of the history or alchemy during the ele venth and twelfth centuries. The sciences had then begun to decline in the eastern world, and had only shed a faint light upon the western parts of Europe. About the mid dle of the thirteenth century, Albertus Magnus, Roger Bacon, Raymond Luily, and Arnoldus the Villanova, by their writings and examples attracted the attention of learned men to the subject of alchemy. The preten sions of alchemists became more bold than at any for mer period. They professed to develope the constituent principles of gems, awl to communicate processes by which they might be produced. The discovery of the philosopher's stone was now supposed not only to give the power of forming the precious metals, but to in volve many wonderful mysteries in religion and science.
During the fourteenth and fifteenth centuries, the impulse which Roger Bacon and his contemporaries had given to the public mind, was maintained by the abili ties of several philosophers, and by the example of dif ferent princes and men of rank, who engaged in this delusive pursuit. By their influence, the belief in al chemy became almost universal ; and impostors, who pretended to possess the philosopher's stone, and to teach the secret ler a sum of money, were enabled to profit by the credulity and ignorance of the times. These impositions at length alarmed the higher ranks in so ciety, and brought the whole class of alchemists into disrepute. Laws were enacted against them by the different princes of Europe ; and men of learning began to dispute the practicability of transmuting the metals, and to question the validity of the evidence that such transmutations had ever been effected.
Another branch of alchemy, viz. that of forming an medicine, began about this period to rise into celebrity. The chief supporter of this empiricism was the celebrated Paracelsus, who, in the sixteenth century, by a bold administration of chemical preparations, cured several diseases w l ieh trans ended the pow er of th( feeble medicines then in use. Ills death, in the .17th year of his age, alter haying pretended to possess the univeral remedy', and promised by means of it to confer lo:-,gevity on his patients, gave a shock to this branch of alchemy, bout winch it iiv‘er rc covered. In consequence of these events, and of the gradual improvements in knowledge which enabled learned rich to perceive the fallacies by which their predecessors had been misled, and to detect the impostures of those is Ito, trout 11111C to time, pretended to perform transmutations, the study of alchemy, after a gradual decline during the seven teenth and eighteenth centtn ies, has now totally disap peared.
One naturally' feels a desire to know by what theories the alchemists guided their researches in pursuit of the philosopher's stone, and by what processes they directed their disciples to kirm this invaluable substance. l I we have recourse to their writings with this view, we shall be astonished at tin impenetrable obscurity in which the y are involved. The alchemists pretend, that the know
ledge of the philosopher's stone was reserved by Provi dence for a few select persons, who, by a diligent study of the alchemical authors, by patient perseverance in the pursuit of experiment, and by an truldemished course of virtue, had rendered themselves worthy of having this secret revealed to them. They accordingly threatened, with the severest vengeance of Ilcaven, both in this and a future state, that person who should counteract the designs of Providence by disclosing this divine art to the profane vulgar. Their books were, therefore, written in a style of studied obscurity, in order that none but the peculiar favourites of Heaven might be able to un derstand them. Some of these writers adopt such mys tical modes of expression, or employ such peculiar dia grams and symbols, as to be absolutely unintelligible ; while others, after professing to speak plainly, and for some time employing the known terms of chemistry, suddenly disappoint our expectations. Just as we begin to flatter ourselves that we understand their processes, and perceive the particular object which they have in view, they tell us that the copper or the silver which they have immediately before commanded us to employ, is (non a'ulgi sed nos!ram,) not the copper or silver of the vulgar, but of philosophers. When, after deluding their readers in this manner, they conclude by an (intel lige potes,)—understand me if you can (si Pure dieerem etiant fineri intelligerent,) if 1 should more, even children would understand ;—we can scarcely help believing, that their works were intended rather to ridi cule than explain the science. Thus the unhappy per sons who addicted themselves to the study of alchemy always remained uncertain how to interpret the author whom they chose as their instructer; and instead of be ing led, from the unfortunate issue of their experiments, to doubt the authority of their guide, and desist from 4he pursuit, rather supposed that they had misun derstood the author; and attempted, by a more attentive study' of his works, to arrive at his true meaning. They were thus led on front one delusive hope to another, from one expensive process to another still more expen sive, till the complete expenditure of their own funds, and the failure of their credit with others, forced them unwillingly to desist from their experiments. After haying thus spent their lives in perpetual labours and disappointments; after having injured their health by the processes in which they were employed; and redu ccd themsek es to absolute poverty, in their chase after an imaginary object, the alchemists were seldom cured of their folly, but indulging, in retirement, in their vi sionary speculations, they at last, either from mental de rangement, or from the want of funds sufficient to dis prove their new theory by experiment, believed them selves to ha, e become acquainted with the mode of forming the philosopher's stone ; and composed mystical books to teach the art to others.