In recent years, the interest of a number of investigators has centered on the question of liver function. It is hardly necessary at the present time to discuss these tests in detail as a review by Delprat and Whipple1 covers much of this ground. Whipple and Pelkan2 have recently reported experiments which indicate that phenol conjugation is a function of the liver which gives information of value in a study of the physiology of the liver. Phenol ingestion is too toxic for clinical use. Many papers3 dealing with the injection of phenoltetrachlorphthalein have appeared during the past few years. This dye is eliminated promptly from the blood by the liver and appears in the bile and intestine. Various methods of recovery of the dye from the feces or duodenum have been used, but this test is inaccurate when there are abnormalities of the biliary passages and therefore has obvious clinical