Realizing the importance of an accurate measure of liver function in the diagnosis, prognosis and treatment of toxemias of pregnancy, many investigators have tried to devise tests by means of which the functional capacity of the liver can be estimated under normal and pathologic conditions. Various methods have been attempted. Examination of feces and urine for the presence or absence of stercobilin, bilirubin, urobilin and the biliary salts has its place and can be clinically applied to a certain degree. Determination of the glycogenic and glycolytic functions, the proteolytic function, the proteopexic hemoclasis crisis test of Widal, and the various blood examinations have all been utilized with varying results. Based on the fact that the liver has important excretory as well as secretory powers, several coloring matters have been used, chief among which is phenoltetrachlorphthalein. Abel and Rowntree,1by means of pharmacologic studies, determined that phenoltetrachlorphthalein is excreted almost