Evans blue or dye T-1824 is an azo dye produced by an interaction of o-tolidine with Chicago acid (1-amino-8-naphthol-2,4-disulfonic acid) and has a molecular weight of 960 (Gregersen and Rawson,1 Rawson2). It has been used for a number of years by numerous workers for the determination of total plasma volume in man and experimental animals3 and has been tried in the treatment of experimental cancer.4 In spite of the relatively extensive administration of this dye, almost nothing is known concerning its toxic properties.
The experiments to be reported were undertaken for the purpose of providing at least some fundamental data on this aspect.
EXPERIMENTAL PROCEDURE AND OBSERVATIONS
The dye used was synthesized by Dr. C. Lischer, of the Warner Institute for Therapeutic Research, and was purified so as to conform with the standards established for this dye by Gregersen, according to spectroscopic methods. In accordance with