Many have commented upon the strange odor that pervades the back wards of mental hospitals.1-6 A few have maintained that “there is an odour peculiar to the insane, which is not met with in ordinary hospitals for the sick, however dirty they may be.”7 This unusual “odor” seems to be especially intense in the room where insulin therapy is given, and the odor appears to come from the skin of the patients, particularly those catatonic patients with greasiness of the skin. Among the symptoms of catatonia a recent textbook lists a “peculiar odour of the patient’s sweat which is difficult to describe.”8 A recent article mentions “four patients, who for years had a skunk-like odor, which no amount of bathing changed,”9 and these patients were all catatonic schizophrenics.10 If there is a unique “odor” in the apocrine sweat or in the sebaceous