A married man aged 53 reported to the venereal diseases clinic in March, 1949, when he was found to have syphilis with an early secondary rash. A penile sore was present, and the Wassermann reaction was strongly positive. Treatment with Stabilarsan and bismuth was begun, and he received a total of 16-2 g. of the former, and 5 7 g. of the latter (a normal course) between March, 1949, and January, 1950, when he was given his last injection. About December, 1949, he had begun to complain of lassitude and anorexia, and in January, 1950, he became increasingly pale and dyspnoeic on exertion. On March 18, 1950, he was admitted to Darlington Memorial Hospital in an extremely pale and semi-comatose condition with temperature 98 0° F., pulse 120, and respiration 30. No icterus was present. There was a good deal of dental caries and pyorrhoea together with a severe stomatitis and gingivitis. In addition, a bluish-grey line was visible near the gum margins, and there were small patches of similar pigmentation on the mucous membrane of the cheeks. There was a moderate degree of sacral but no ankle oedema, and the neck veins were distended. No cutaneous or retinal haemorrhages were visible, and there was no enlargement of superficial lymph nodes. The liver could be felt, firm and smooth, with a regular edge, 4 cm. below the costal margin, but the spleen was not palpable. No cardiac enlargement could be made out clinically; there was a soft apical systolic murmur, and many crepitations were heard at the lung bases. The blood pressure was 110/80. The capillary resistance test was positive. The urine contained a trace of albumin. On admission, haemoglobin was 16 per cent. (14 g. = 100 per cent.); red blood cells 730,000 per c.mm., white blood cells 7250 per c.mm. (polymorphonuclear * Received for publication October 6 1953. leucocytes 74 per cent., lymphocytes 25 per cent., monocytes 1 per cent.), platelets 208,000 per c.mm. A stained film showed the red cells to be normal in size, shape, and staining. No primitive cells were seen. Treatment with penicillin and iron was commenced, and packed cells from three pints of blood were given slowly during the first 2 days, the haemoglobin rising to 48 per cent. on March 21, 1950. Intramuscular injections of B.A L. (2,3 dimercaptopropanol) were started on March 19, 1950 (2 ml. intramuscularly four times on the first day, twice daily for 4 days, and then daily for 2 days). The general condition of the patient improved rapidly, although he was for some days very confused and required sedation with paraldehyde. By March 31, the oral sepsis had largely disappeared, though the pigmentation persisted. After the first day there was no albuminuria, and the specific gravity of the urine rose on occasions to 1,020. Sternal puncture was performed on March 21, the count on films made from the aspirated marrow being as in Table I. Radiography on March 27, 1950, showed generalized enlargement of the heart and