1738
EVELYN M. HANCOCK AND ARTHUR C. COPE
Vol. 66
tenic groups are closer together thar, in XXXV. The antiserum also precipitates X-ovalbumin, made by coupling p-aminobenzoic acid with ovalbumin. The dependence on the PH of the system of the amount of precipitate formed by anti-X serum benzoate ion H O , D C < : and the p- with XXXV and with X-ovalbumin was studied. The effect of each of 56 haptens in inhibiting precipitation was also investigated, and the data nitrophenolate ion - O a - - N < Z , were interpreted with use of a quantitative theory based on the assumed heterogeneity of the antiO=a=N