Symptoms of mild toxicity such as malaise, lassitude, weakness, headache, dizziness, depression, anorexia and nausea are frequently encountered in patients receiving sulfanilamide. Less commonly tinnitus, mental confusion, paresthesias, dyspnea, inability to concentrate, diarrhea, constipation and vomiting are observed. In unusual instances there is difficulty in micturition, slowing of the stream and loss of force. Lowering of the carbon dioxide combining power is not uncommon. With rare exceptions, the drug can be given despite these manifestations. CYANOSIS Some degree of cyanosis is present in 90 per cent of the cases in which the drug is used. It varies from a mild bluing of the lips or nail beds to an intense slaty discoloration of the entire body. It usually appears shortly after treatment is started, may disappear during the course of treatment and uniformly disappears within a few days after the use of the drug is stopped. The cyanosis is due