In the treatment of chronic skin diseases which often resist the usual therapeutic measures, any new method of therapy that causes a more rapid and effectual disappearance of the lesions is worthy of investigation. This is particularly true of psoriasis, which is widely prevalent, and many times resists our best efforts to clear up the lesions. On account of its obscure etiology most forms of treatment have been used empirically, which probably accounts for the great variety and diversity of the methods employed.
Chrysarobin, first used by Keith in 1877, is probably the best known remedy, but possesses many disadvantages and does not always relieve the chronic cases. In treating these obstinate cases, strong preparations of chrysarobin have been used; but on account of the dermatitis produced, they could not be applied for long periods of time, necessitating an interrupted and long drawn out course of treatment. Chrysarobin also has