The Normal Pigment of the Urine. Iv. Preliminary Study of the Properties of the Pig- Ment Obtained by the New Method of Butyl Alcohol Extraction.*

In the preceding paper (1) a new method of preparing the normal pigment from urine has been described. It consisted essentially of extracting the pigment from acidified urine (pH about 4.0) with n-butyl alcohol, washing freely at different stages in the procedure with water, chloroform, benzol, amyl acetate, and amyl alcohol and finally obtaining the pigment product in a dry form by washing with anhydrous absolute alcohol and anhydrous ether. The purpose of this communication is to describe briefly a number of preliminary studies which indicate that the normal urinary pigment has not been altered significantly during the course of preparation and that it has been prepared in probably a higher state of purity than hitherto. Some further evidence also has been adduced to show that the pigment is a chemical entity and not a mixture of substances.