1. In these studies several phases of the predpitm reactions were investigated by the use of purified proteins as antigens. These preparations were edestin from hemp-seed and crystalline ovalbumin from fresh eggs. The ovalbumin, isolated by the method of Hopkins and Pinkus,.was apparently as pure as is obtainable by chemical means. This albumin, however, produced moderately severe anaphylactic ...

1. The reaction between crystalline horse serum albumin and homologous antibody in rabbit sera is quantitatively accounted for by expressions similar to those derived from the law of mass action for other immune precipitating systems. 2. The reaction of an azo dye prepared from crystalline serum albumin by coupling with diazotized R-salt-azo benzidine was also studied with homologous antibody a...