The _Phrygian-stone_ was a pumice with alum and some other ingredients. Dioscorides says it has astringent, cleansing, and moderately escharotic powers, and proves a remedy for burns. (v, 140.) Galen professes to have had great experience of it in diseases of the eyes. (Ed. Basil. t. ii, 122, 208.) See also Avicenna (ii, 2, 405.) The _Ageratus_ does not occur we believe in Dioscorides or Pliny. Galen calls it a stone which the curriers of leather use. He says it is astringent and acrid, and recommends it particularly in inflamed uvula. Avicenna copies from him. (ii, 2, 409.) The _Anthrax_ or _Carbuncle_ of the ancients comprehended the ruby and a multitude of other gems of the same colour. It was scarcely used in medicine. De Boet says that the _Asian-stone_ is light and spongy, and contains alum, nitre, and salt. Dioscorides calls it slightly septic and discutient, and recommends it as an application to old, and more especially fungated, ulcers, and those of a malignant nature. The flower of it, by which was meant an efflorescence on the surface of it, he says does good in phthisis. He further says of it, that a hip-bath prepared with it is highly beneficial in the cure of gout. (v, 141.) Galen and the other authorities treat of it in more general terms. (De Simpl. ix.) See also Serapion, who merely copies from Dioscorides and Galen. (c. 393.) The _Amethyst_ of our times is the same gem that the ancients knew by this name. Except that it was suspended from the neck as an amulet to prevent drunkenness, we are not aware that it was used in medicine. See Pliny (H. N. xxxvii, 40); Marbodeus (De Lapid. 4.) The _Gagate_ is a fossil, bituminous substance, containing carbon and ethereal oil. It is jet. The _Thracian-stone_ was similar to it; indeed, we suppose, a variety of it. The Gagate was used by the ancients as a test of epilepsy, and a restorative from hysterical fits. Galen gives an interesting account of his experience in the medicinal use of gagate and Thracian-stone, the result of which is, that he found gagate rather to weaken than increase the powers of the bitumen which he had picked up upon the shores of the Dead Sea; but that as a desiccant, it operated beneficially in the cure of sores, and that not only of recent, but also of sinuous ulcers. (De Simpl. ix.) He mentions that he could not discover the river Gagas in Lycia, from which, according to Dioscorides, this stone derives its name. (Ibid.) There is an interesting description of the Thracian-stone in a passage of Nicander quoted by Galen, under this head, _Theriac_. (45.) The Arabians who treat of it merely copy from the Greeks. See Rhases (Cont. l. ult. 399, 400), and Avicenna (ii, 2, 107.) Mesue gives a formula for an oil of gagate. (De Oleis, i.)