METHODS

The following methods were used to determine the values under consideration in this study. The blood urea nitrogen was determined by the method of Archibald (4); blood non-protein nitrogen and non-protein nitrogen of the bath by the method of Daly (5); serum chloride by the method of Schales and Schales (6); serum CO2 combining power by the manometric method of Van Slyke ([7], p. 269); total serum baseby the method of Sunderman (8); potassium and sodium were determined by the flame photometer using the internal lithium standard (9); determination of the uric acid of the serum and the dialysate was done by the method of Kern and Stransky (10); and the urea nitrogen of the bath was determined by the method Van Slyke ([7], p. 490). The serum and bath inorganic phosphate was determined by the method of Fiske and Subbarow (11) and serum calcium was done by the method of Clark and Collip (12). Hematocrits were estimated by the method of Wintrobe (13), while clotting times were performed by the tube method of Lee and White (14). The heparin tolerance test was done according to the method of de Takats (15).

As a guide to adjustment of the tonicity of the bath fluid, we use theestimation of the serum melting point (2). As closeto the time of dialysis as is practical, 25 cc. of blood are drawn from the patient and the serum melting point determinedby 425