No one can gainsay the inadequacy, in many respects, of presentday methods of investigating the functional efficiency of the liver. General recognition of this fact apparently has led to the feeling among many clinicians that little information can be obtained by these methods. As a result, little or no attempt is made to determine the state of hepatic function in many clinics in which elaborate studies of renal function, for example, may be a matter of routine. My experience in this field has convinced me of the value of a careful and detailed study of hepatic function by readily available methods in a great variety of clinical disorders, and it has led to the belief that much of the discredit which is attached to these procedures is due to errors of interpretation rather than to faults inherent in the methods. The present report consists of observations made on patients with