CHEMICAL MECHANICS OF COAGULATION 271 



by alkalies Robertson and Miyake (11) have also been led to 

 infer that alcohol induces polymerization of the casein molecules 

 even in solutions of sodium caseinate in 20 to 30 per cent alcohol. 

 From the above results, however, we must infer that if in such 

 solutions the mass of the casein ions is doubled their valency 

 must also be doubled, for otherwise p would be halved and the 



observed constancy of the ratio — ^^— in these solutions would 



^HjO.alc. 



not be obtained. 



Incidentally, the profound diminution in the degree of disso- 

 ciation of the caseinate which results when the alcohol-concen- 

 tration attains a certain value explains, independently of any 

 theory as to the mode of dissociation of the protein salts in solution, 

 the observed fact that alcohol precipitates protein salts as such 

 from their solutions (Cf. Chap. IV, 2) and not the uncombined 

 proteins, since, previously to their precipitation, the combined 

 base or acid is bound up in an undissociated molecule. 



LITERATURE CITED 



(1) Arrhenius, S., Zeit. f. physik. Chem. 1 (1887), p. 285. 



(2) Cohen, E., Zeit. f. physik. Chem. 25 (1898), p. 31. 



(3) Jones, H. C, and Collaborators, Amer. Chem. Journ. 28 (1902), p. 



329; 32 (1904), p. 521; 34 (1905), p. 481; 36 (1906), pp. 325 and 

 427; 37 (1907), p. 405; 41 (1909), p. 433; 42 (1909), p. 37. Zeit. f. 

 physik. Chem. 61 (1908), p. 641; 62 (1908), p. 41. 



(4) Osborne, W. A., Journ. Physiol. 27 (1901), p. 398. 



(5) Ostwald, W., and Luther, R., Phys.-chem. Messungen, 2 Aufl. p. 260. 



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



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



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



(9) Robertson, T. Brailsford, Journ. physical Chem. 15 (1911), p. 387. 



(10) Robertson, T. Brailsford, and Burnett, T. C, Joiirn. Biol. Chem. 6 



(1909), p. 105. 



(11) Robertson, T. Brailsford, and Miyake, K., Journ. Biol. Chem. 26 (1916), 



p. 129. 



(12) Roth, W. A., Zeit. f. physik. Chem. 42 (1903), p. 209. 



(13) Thorpe, T. E., and Rodger, J. W., Phil. Trans. Roy. Sec. London, 



185A (1894), p. 397. 



(14) Walden, P., Zeit. f. physik. Chem. 55 (1906), p. 209. 



