In the illustration (p. 65), which is taken from an authentic engraving of the sixteenth century, we have a figure of the apparatus used for distilling the “Water of Life,” the process for which is described by Gesnerus in the _Newe Jewell of Health_, printed in 1576. The alchemist, arrayed in his imposing robes, is depicted giving instructions to his assistant as to certain precautions to be taken in conducting the process. Bacon states that sulphur and mercury are the mineral roots and natural principles upon which Nature herself acts and works in the mines and caverns of the earth; the latter metal he believed to be the true elixir of the philosopher’s stone; others, including Rhazes and Merlin, believed it to be an amalgam of gold and mercury, fantastically called the Red man and his White wife. Concerning the vessels for producing this “Citrine body,” as Bacon calls it, the most exact precautions were taken. Special apparatus was used, and a special heat, which was not to exceed the heat of the body. For this purpose horse-dung was employed. Senier, the philosopher, says: “Dig a sepulchre and bury the woman (mercury) with her man (gold) in horse-dung, the fire of the philosopher, until such time as they be conjoined”. Bacon’s definition of alchemy was: “Alchymie is the art or science teaching how to make or generate a certain kind of medicine which is called the elixir. It teaches how to transmute all kinds of metals, one with another; and this by a proper medicine.” George Ripley, a monk, in 1476, thought that he had discovered the much-coveted stone in pure sulphur. He says: “Let the two sulphurs, _viz._, the white and the red, be mingled with the oil of the white elixir that they may work the more strongly, and you shall have the highest medicine in the world to heal and cure human bodies, and to transmute the bodies of metals into the most pure fine gold and silver”. Berthelot, who has made an exhaustive study of the subject, comes to the conclusion that the doctrines of alchemy concerning the transmutation of metals, did not originate in the philosophical views of the constitution of matter as generally supposed, but in the practical experiments of goldsmiths occupied in making fraudulent substitutes for the precious metals. One cannot but think with pity of the immense labour expended and lost in the attempt made by many of these pioneers of science in their pursuit after this chemical chimera.