The infant was breast-fed and sucked well. However, he failed to gain weight, and on the 15th day began to vomit occasionally. On the 19th day he was transferred to the Children's Ward for further investigation. He then weighed 2065 g., was marasmic, wide-eyed, and thirsty, with a rectal temperature of 39*4 'C.( Fig.). Blood sugar, 720 mg./100 ml.; CSF sugar, 405 mg./100 ml.; CSF protein, chloride, and cell count normal; blood urea, 77 mg./100 ml.; urine contained 2% sugar but no ketones.A subcutaneous infusion of 1/5 normal saline was given. All urine voided was collected and tested for sugar and acetone. Soluble insulin was given two or three times daily in doses ranging from 2 to 6 units.Ketones were never found in the urine. Administered insulin totalled 12 units daily for most of the first fortnight, but thereafter the dose gradually fell. No attempt was made to keep the urine entirely sugarfree because of the particular dangers of hypoglycaemia in infancy. However, at 5 weeks a brief hypoglycaemic convulsion occurred which was terminated by intravenous glucose. From the start of treatment there was immediate clinical improvement and a steady gain in weight.At 6 weeks intermittent vomiting, abdominal distension, fever, and diarrhoea developed, associated on three occasions (2, 3, and 6 January 1964) with serum potassium over 7 mEq/l., and with low sodium and chloride levels. On these dates blood sugar levels of 550, 770, and 60 mg./100 ml. were recorded. The 24-hour urinary 17-oxosteroid and total oxogenic steroid excretion (5-6 January) were 0 * 15 and 0 * 64 mg., respectively. Blood urea was 30 mg./100 ml. and blood culture was negative. There was a tachycardia of 200/min., and the systolic blood pressure in the arm by the flush technique was 75 mm. Hg. Adrenal insufficiency was suspected and desoxycorticosterone acetate 1 mg. daily and subcutaneous 1/5 normal saline were administered from [7][8][9][10]