In the translation of Avicenna it is likewise described by the name of impetigo. It is called a species of dry achor, by which is no doubt meant papula. It is stated that it has a tendency to pass into lepra or psora. The remedies which are recommended are human saliva, the chaste tree, capers, leeches (which are not mentioned by the Greeks), likewise gum arabic dissolved in vinegar, mustard and vinegar, salt water, the roots of king’s spear, &c. Haly Abbas recommends stimulant liniments of a similar kind. Rhases briefly recommends lotions of vinegar and ammoniac, and, when it becomes inveterate, leeches, strong friction, &c. His translator also misapplies the term impetigo to it. The lichen appears to be the cutaneous complaint which Alsaharavius describes by the name of _alcoab_. He represents it as a superficial ulceration, and mentions four species of it. Dr. Willan confirms the statement of the ancient authorities, that the disease has a tendency to pass into lepra and psora. The species called _lichen tropicus_ by Dr. Willan, seems to be the _hidroa_ of Hippocrates (Aph. iii, 21); the _sudamen_ of Pliny (xxiii, 45); one of the _essere_ of Haly Abbas (Theor. viii, 17); one of the _alsara_ of Alsaharavius (Pract. xxx, 8); and the _hasef_ of Avicenna (iv, 7, 3, 8). See also Galen’s ‘Commentary’ (v, 261); ed. Basil. Galen says it is attended with pruritus, asperity, and ulceration. Avicenna and Rhases particularly commend bleeding, cleansing the skin, and the cold bath. Most of Rhases’ authorities in his ‘Continens,’ recommend for the _asaf_, or sudamen, cooling and astringent applications, containing roses, myrtles, galls, sandals, camphor, and the like. They attribute the complaint to profuse perspiration. In certain cases, Rhases directs us to allay the pruritus or tingling, with hot water and the flesh of melons. He also approves of purging with tamarinds and myrobalans. (Cont. xxxvi.) See also ad Mansor. (v, 30). Mercurialis is of opinion that Virgil alludes to the sudamina in the following lines: “Verum etiam invisos si quis tentarat amictus, Ardentes papulæ atque immundus olentia sudor Membra sequebatur.” (Georg. iii, 565.)