Chrysarobin is a neutral principle extracted from Goa powder, a substance found deposited in clefts or cavities of the wood of the araroba tree of Brazil. It is an orange-yellow powder, tasteless and odorless, but irritating to mucous membranes if continuously applied. Practically its only use at present is in psoriasis, the 5 per cent. ointment being employed. This is not used about the face, as it may cause irritation of eyes, nose, and mouth. It sometimes causes an acute dermatitis of arms or legs.