It is usually an obstinate disease, but curable. Some cases yield readily, others are exceedingly rebellious, especially acne of the back. Success depends in a great measure upon a recognition and removal of the predisposing condition. Treatment is ordinarily a matter of months. #What measures of treatment are usually demanded in acne?# Constitutional and local measures; the former when indicated, the latter always. #Upon what is the constitutional treatment based?# Upon indications. Diet and hygienic measures are important. In dyspepsia and constipation, bitter tonics, alkalies, acids, pepsin, saline and vegetable laxatives, are variously prescribed. Special mention may be made of the following:-- [Rx] Ext. rhamni pursh. fl., .............. f[dram]ij-f[dram]iv Tinct. nucis vom., ................... f[dram]iij Tinct. cardamomi comp., .......q.s. ad [Oz]iij. M. SIG.--f[dram]t.d. Or Hunyadi Janos or Friedrichshall water may be employed for a laxative purpose. In chlorotic and anaemic cases the ferruginous preparations are of advantage. Cod-liver oil is often a remedy of great value, and is especially useful in strumous and debilitated subjects. Calx sulphurata in pill form, one-tenth to one-fourth grain four or five times daily, is said, acts well in the pustular variety. In some instances, more particularly in sluggish papular acne, arsenic, especially the sulphide of arsenic, acts favorably. Upon the whole, the line of treatment that keeps in view proper and healthy action of the gastro-intestinal canal is the most successful. [Illustration: Acne of back.] In inflammatory cases occurring in robust individuals the following is often of service:-- [Rx] Potassii acetat., .................... [dram]iv Liq. potassae, ........................ f[dram]ij Liq. ammonii acetat., .... q.s. ad ... f[Oz]iij. M. SIG.--f[dram]j-f[dram]ij t.d., largely diluted. #State the character of the local treatment in acne.# This must vary somewhat with the local conditions. Cases which are acute in character, in the sense that the lesions are markedly hyperaemic, tender and painful, require milder applications, and in exceptional instances soothing remedies are to be prescribed. As a rule, however, stimulating applications may be employed from the start. The remedies are, for obvious reasons, most conveniently applied at bedtime. #What preliminary measures are to be advised in ordinary acne cases?# Washing the parts gently or vigorously, according to the irritability of the skin, with warm water and soap; subsequently rinsing, and sponging for several minutes with hot water, and rubbing dry with a soft towel; after which the remedial application is made. In sluggish and non-irritable cases sapo viridis or its tincture may often be advantageously used in place of the ordinary toilet soap.