250 ELECTROCHEMISTRY 



while in reacting with diacid bases two COH.N groups are 

 involved, part of the valencies of the ions which are formed suffer- 

 ing internal neutralization thus: 



-CO++ H 



2 -COH.N- + Ca(OH) 2 = /Ca + ^N- 



/ I 



-CO.N- OH 



/ \ 

 H OH 



If this view be correct, then one molecule of calcium hydrate 

 must obviously bind twice the weight of casein that is bound 

 by one molecule of KOH. Hence di- and monacid bases unite 

 with casein in equivalent-molecular proportions, but at "satu- 

 ration" of the base with casein, when the mass of the protein 

 ions is at its maximum, the cations formed as a result of the 

 union with diacid bases, being much more bulky than those 

 formed by the union with monacid bases, fail to pass into solu- 

 tion. Hardy (2) has found that bases dissolve serum-globulin, 

 not in equivalent molecular but in molecular proportions. It is 

 probable that in this case also an insoluble salt is formed with 

 the minimal proportion of diacid base. 



LITERATURE CITED 



(1) Bredig, G., Zeit. f. physik. Chem. 13 (1894), p. 191. 



(2) Hardy, W. B., Journ of Physiol. 33 (1905), p. 251. 



(3) Kossel, A., Zeit. f. physiol. Chem. 25 (1898), p. 165. 



(4) Kossel, A., and Dakin, H. D., Zeit. f. physiol. Chem. 41 (1904), p. 412. 



(5) Osborne, W. A., Journ. of Physiol. 27 (1901), p. 389. 



(6) Robertson, T. Brailsford, Journ. Biol. Chem. 2 (1907), p. 337. 



(7) Robertson, T. Brailsford, Journ. physical Chem. 11 (1907), p. 437. 



(8) Robertson, T. Brailsford, Journ. physical Chem. 11 (1907), p. 542. 



(9) Robertson, T. Brailsford, Journ. Biol. Chem. 5 (1908), p. 147. 



(10) Robertson, T. Brailsford, Journ. physical Chem. 12 (1908), p. 473. 



(11) Robertson, T. Brailsford, Journ. physical Chem. 13 (1909), p. 469. 



(12) Robertson, T. Brailsford, "The Proteins," Univ. of California, Publ. 



Physiol. 3 (1909), p. 115. 



(13) Robertson, T. Brailsford, Journ. physical Chem. 14 (1910), p. 377. 



(14) Robertson, T. Brailsford, Journ. physical Chem. 14 (1910), p. 528. 



(15) Robertson, T. Brailsford, Journ. physical Chem. 14 (1910), p. 601. 



(16) Robertson, T. Brailsford, Journ. physical Chem. 14 (1910), p. 709. 



(17) Robertson, T. Brailsford, Journ. physical Chem. 15 (1911), p. 166. 



