Galen, after describing its alexipharmic properties, states that he tested it by causing a number of fowls to be dosed with it. To these he brought others to which no theriaca had been given. The poison was administered to all. The fowls to which the theriaca had been given all survived, and all the others died. Galen’s encomiums on this compound were no doubt largely responsible for the marvellous reputation it enjoyed all through the centuries in which his authority was accepted. He declares that it resists poison and venomous bites, cures inveterate headache, vertigo, deafness, epilepsy, apoplexy, dimness of sight, loss of voice, asthma, coughs of all kinds, spitting of blood, tightness of the breath, colic, the iliac passion, jaundice, hardness of the spleen, stone, urinary complaints, fevers, dropsies, leprosies, the troubles to which women are subject, melancholy, and all pestilences. Down to the seventeenth century these virtues were almost universally accepted, and many were the learned treatises written to explain its action; how one drug toned down the effect of others, and how the whole formed a sort of harmony in medicine. At the same time most of the old masters in pharmacy fancied they could suggest some improvement, and the original formula was modified in scores of ways. In addition there arose new electuaries, modelled more or less closely on theriaca, but perhaps devised for some special complaints, and bearing the names of their authors. Many of these also attained to considerable fame. For some centuries the theriaca made in turn at Constantinople, Cairo, Genoa, and Venice was in such reputation that customers would have it so branded. Ultimately the last-named city secured almost the monopoly of the manufacture. A reference to its production there occurs in Evelyn’s Diary, dated March 23, 1646. Evelyn writes: “Having packed up my purchases of books, pictures, casts, treacle, &c. (the making and extraordinary ceremony whereof I had been curious to observe, for it is extremely pompous and worth seeing), I departed from Venice.”