SummaryThe«cephalin-cholesterol flocculation»test of Hanger has been applied to several groups of patients suffering from hepatic diseases : hepatitis, obstructive jaundice, post-arsenical jaundice and cirrhoses. The tests of Takata, Gross, Weltman, and the dosage of blood phosphatases have been tried on the blood of those patients. The technic of the tests is described and results discussed.In case of hepatitis Hanger test is always positive while Takata, and Gross and Weltman tests give no constant results. The blood phosphatases rise generally to less than 10 U.R. In case of obstructive jaundice Hanger test is sometimes positive (5 times on 15 cases), chiefly when the icterus has lasted for several weeks. In those cases, Takata and Gross tests may also be positive.The blood phosphatases rises generally higher than 10 U.R.Applied to postarsenical jaundices the tests give no conclusive evidence. They are constantly positive in cirrhosis of the liver.An attempt to determine an index of liver damage is proposed, which would allow to differentiate the hepatitis from the obstructive jaundices.