This is quoted by Glauber from Conrad Khunrath in his Medulla destillatoria, and he adds: "I some time since administered this Oil of gold for eight or ten days successively to an Infant for the freeing his body from mercury." (Glauber's Works, Packe's translation, London, 1689.)
Robert Boyle, in his Usefulness of Natural Experimental Philosophy (1663), expresses doubts as to the "strange excellency" of aurum potabile, remarking that "learned physicians and chymists have pronounced the preparation of potable gold as itself unfeasible." And he adds: "I should much doubt whether such a potable gold would have the prodigious virtues its encomiasts ascribe to it and expect from it; for I finde not that those I have yet met with deliver these strange things upon particular experiments duly made, but partly upon the authority of chymicall books, many of which were never written by those whose names they bear." He then proceeds to blame physicians for using expensive medicines and says: "T'were a good work to substitute cheap ones for the poorer sort of patients."
The change of opinion as respects the therapeutic value of gold, foreshadowed in the quotation from the astute Boyle, is well shown by comparing the passages on the subject in two different editions of Lémery's Cours de Chymie, one published in 1680 and one in 1730. In the earlier edition of Lémery's very successful work we read: "Gold is a good remedy for those that have taken too much mercury, for these two metals do easily unite together, and by this union or amalgamation the mercury fixes and its motion is interrupted." (Page 25.) "Aurum fulminans causes sweat and drives out ill humors by transpiration. It may be given in the small pox two to six grains in a lozenge or electuary. It stops vomiting and is also good to moderate the active motion of mercury." (Harris's translation, London, 1680, page 9.)
And in the later edition, the eleventh of the series, Lémery or his editor makes a very different statement:
"Potable gold, so much praised by the alchemists, and sold so dear by them, is commonly only a vegetable or mineral tincture of a color resembling gold, and as they make this tincture with a spirituous menstruum, it sometimes excites perspiration. This effect they ascribe to the gold, although the metal has rarely anything to do with it." (1730.)
In the works of Caspar Neumann a passage occurs that expresses so clearly the present views of many that it is hard to realize it was written nearly one hundred and fifty years ago. Neumann writes:
"Gold has been imagined to be possessed of extraordinary medicinal virtues, and many preparations, dignified with the name of this precious metal, have been imposed upon the public;
