The possibility of chemical gold making was not conclusively disproved by scientific evidence until the 19th century. As rational a scientist as Sir Isaac Newton (1643-1727) had thought it worthwhile to experiment with it. The official attitude toward alchemy in the 16th to 18th century was ambivalent. On the one hand, The Art posed a threat to the control of precious metal and was often outlawed; on the other hand, there were obvious advantages to any sovereign who could control gold making. In "the metropolis of alchemy," Prague, the Holy Roman emperors Maximilian II (reigned 1564-76) and Rudolf II (reigned 1576-1612) proved ever-hopeful sponsors and entertained most of the leading alchemists of Europe.
This was not altogether to the alchemist's advantage. In 1595 Edward Kelley, an English alchemist and companion of the famous astrologer, alchemist, and mathematician John Dee, lost his life in an attempt to escape after imprisonment by Rudolf II, and in 1603 the elector of Saxony, Christian II, imprisoned and tortured the Scotsman Alexander Seton, who had been traveling about Europe performing well-publicized transmutations.
The situation was complicated by the fact that some alchemists were turning from gold making not to medicine but to a quasi-religious alchemy reminiscent of the Greek Synesius. Rudolf II made the German alchemist Michael Maier a count and his private secretary, although Maier's mystical and allegorical writings were, in the words of a modern authority, "distinguished for the extraordinary obscurity of his style" and made no claim to gold making. Neither did the German alchemist Heinrich Khunrath (c. 1560-1601), whose works have long been esteemed for their illustrations, make such a claim.
Conventional attempts at gold making were not dead, but by the 18th century alchemy had turned conclusively to religious aims. The rise of modern chemistry engendered not only general skepticism as to the possibility of making gold but also widespread dissatisfaction with the objectives of modern science, which were viewed as too limited. Unlike the scientists of the Middle Ages and Renaissance, the successors of Newton and the great 18th-century French chemist Antoine-Laurent Lavoisier limited their objectives in a way that amounted to a renunciation of what many had considered the most important question of science, the relation of man to the cosmos. Those who persisted in asking these questions came to feel an affinity with the alchemists and sought their answers in the texts of "esoteric," or spiritual, alchemy (as distinct from the "exoteric" alchemy of the gold makers), with its roots in Synesius and other late Greek alchemists of the Venice-Paris manuscript.
This spiritual alchemy, or Hermetism, as its practitioners often prefer to call it, was popularly associated with the supposititious Rosicrucian brotherhood, whose so-called Manifestoes (author unknown; popularly ascribed to the German theologian Johann Valentin Andrea) had appeared in Germany in the early 17th century and had attracted the favourable attention not only of such reforming alchemists as Michael Maier but also of many prominent philosophers who were disquieted by the mechanistic character of the new science. In modern times alchemy has become a focal point for various kinds of mysticism. The old alchemical literature continues to be scrutinized for evidence, because alchemical doctrine is claimed to have on more than one occasion come into the possession of man but always again been lost. Nor is its association with chemistry considered accidental.
In the words of the famous 19th-century English spiritual alchemist Mary Anne Atwood, "Alchemy is an universal art of vital chemistry which by fermenting the human spirit purifies and finally dissolves it. . . . Alchemy is philosophy; it is the philosophy, the finding of the Sophia in the mind."