1. Analyses have been made of the electrolytes and proteins of serum and transudates from human subjects. 2. The distribution ratios of HCO(3), Cl, Na, and H(+) deviated from unity as predicted by the Gibbs-Donnan law for similar heterogeneous systems. 3. Analyses of serum, and of artificial salt solutions approximating edema fluid in composition, after equilibration across collodion membranes ...