There was a theory that the engraving of a design or a monogram on a gem increased its medicinal virtues. Galen doubts this, however. He states that the jasper benefits the chest and the mouth of the stomach if laid thereupon, and for complaints of these parts he recommends a necklace of jaspers hung round the neck and reaching down to the affected part. That he knew would do good. But some recommended that a serpent should be engraved on the stones, and Galen had tried this, but could not discover that the engraved stones were any better than the plain ones (Simp. Med., ix). The idea did not die, however. Mr. King quotes the opinion of Camillo Lionhardo, physician to Cæsar Borgia, to the effect that if precious stones were engraved by a skilful person under a particular influence, that influence would be transmitted to the stone; and if the figure engraved corresponded with the virtue of the stone itself or its natural quality, the virtue of the figure and of the stone would be doubled. Jerome Cardan and other mystic writers of the sixteenth century gave great prominence to precious stones as remedies; and Culpepper after quoting from several of them intimates that he expects some of his readers may consider the accounts given incredible. They declared that the diamond rendered men fearless, that the ruby took away idle and foolish fancies, that the emerald resisted lust, that the amethyst kept men from drunkenness and too much sleep, and so on. Culpepper’s reply to prospective sceptics is that he has named his authorities, and that he knows nothing to the contrary why it may not be as possible for these stones to have the effects attributed to them as for the sound of a trumpet to incite a man to valour, or a fiddle to dancing. Moreover, said Garcius, if the stones applied externally were so efficacious, how much more so would they be if taken internally. THE FOUR OFFICINAL CAPITALS. This description was applied in old medical books to Mithridatium, Venice Treacle, Philonium, and Diascordium. There were writers who ventured to criticise some of the details of composition, or some of the uses frequently made of these compounds, but the possibility of medicine existing without them was hardly contemplated previous to the eighteenth century. Of the two confections first named much has been said in other chapters; but it may be of interest to present here a conspectus of the ingredients of each, comparing the last formulas prescribed in the London Pharmacopœia with what may be regarded as the original compositions. The first pair of formulas are quoted from Galen, who gives the Mithridatium from Damocrates and the Theriaca from Andromachus. Both were in Greek verses. It is not known whether the prescription of Andromachus was versified by Nero’s physician or by his son. ANTIDOTUS MITHRIDATICA DAMOCRATIS.