Patients complaining of an insidious onset of edema and showing heavy proteinuria, a low serum albumin concentration, and high blood fats and cholesterol present the cardinal manifestations of the nephrotic syndrome, or lipemic nephrosis. Current ideas on the etiology, pathology, and treatment of this syndrome have been summarized in recent reviews.* The underlying pathology is in the kidneys, and the first aim of treatment is to promote the healing of the renal lesion, on which the ultimate outcome depends. During the course of the disease, numerous secondary manifestations may appear. In the early stages we commonly see oliguria, retention of sodium and water with edema, and alterations in the concentration of sodium, potassium, or calcium in the blood. Later, especially in those patients with destructive renal lesions, there is progressive azotemia, with acidosis, anemia, and hypertension.† Today we are to consider the disturbances of water and electrolytes in the nephrotic