The disease is often rebellious, but in children and young adults the prognosis is almost invariably favorable, permanent loss of hair being uncommon. The same holds true, but to a much less extent, with the disease as occurring in those of more advanced age. In extensive cases--those in which the hair of the entire scalp finally entirely disappears, and sometimes involves all hairy parts--the prognosis is unfavorable. Only exceptionally does recovery ensue in such instances. The uncertain duration, however, must be borne in mind; months, and in some instances several years, may elapse before complete restoration of hair takes place. Relapses are not uncommon. #How is alopecia areata treated?# By both constitutional and local measures, the former having in view the invigoration of the nervous system, and the latter a stimulating and parasiticidal action of the affected areas. #Give the constitutional treatment.# Arsenic is perhaps the most valuable remedy, while quinine, nux vomica, pilocarpine, cod-liver oil and ferruginous tonics may, in suitable cases, often be administered with benefit. #Name several remedies or combinations employed in the external treatment of alopecia areata.# Ointments of tar and sulphur of varying strength; the various mercurial ointments; the tar oils, either pure or with alcohol; stimulating lotions, containing varying proportions, singly or in combination, of tincture of capsicum, tincture of cantharides, aqua ammoniae, and oil of turpentine. The following is a safe formula, especially in dispensary and ignorant class practice: [Rx] [beta]-naphthol, ..................... [dram]ss-[dram]j Ol. cadini, .......................... [dram]j Ungt. sulphuris, .......... q. s. ad ... [Oz]j M. The cautious use of a five to twenty per cent. chrysarobin ointment is of value. Painting the patches with pure carbolic acid or trikresol every ten days or two weeks sometimes acts well; it should not be applied over large areas nor used in young children. Galvanization or faradization of the affected parts may also be employed, and with, occasionally, beneficial effect. Stimulation with the high-frequency current by means of the vacuum electrode is also of value. When practicable, the Finsen light can be applied with hope of benefit and cure. #Atrophia Pilorum Propria.# (_Synonym:_ Atrophy of the Hair.) #What do you understand by atrophy of the hair?# An atrophic, brittle, dry condition of the hair, and which may be either symptomatic or idiopathic. #Describe the several conditions met with.# As a symptomatic affection, the dry, brittle condition of the hair met with in seborrh[oe]a, in severe constitutional diseases, and in the various vegetable parasitic affections, may be referred to.