REFRACTIVE INDICES 367 



value of a for solutions of caseinates in water to be very small. In 

 fact, if allowance be made for the alteration in the refractive index 

 of the water with varying temperature, I have been unable to 

 observe any alteration in a, distinctly greater than the possible 

 experimental error, between 20 and 40 degrees. According to 

 Herlitzka, however, if egg-albumin be employed, a distinct in- 

 fluence of temperature upon the refractivity of the protein itself 

 can be observed. He interprets his results in the light of the 

 Lorentz-Lorentz modification of Gladstone's law of mixtures (28) 

 (29). 



The utilization of the refractometric method for determining 

 the concentrations of various proteins in solutions and in body- 

 fluids has been discussed in Chap. III. 



LITERATURE CITED 



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(3) Borkel, C, Zeit. f. physiol. Chem., 38 (1903), p. 289. 



(4) Bulow, K., Arch. f. d. ges. Physiol., 58 (1894), p. 207. 



(5) Butterfield, E. E., Zeit. f. physiol. Chem., 79 (1912), p. 439. 



(6) Framm, F., Arch. f. d. ges. Physiol., 68 (1897), p. 144. 



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(10) Gamgee, A., and Jones, W., Beitr. z. chem. Physiol, imd Path. 4 (1903), 



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(11) Gladstone, J. H., and Dale, T. P., Phil. Trans. Roy. Soc. London, 148 



(1858), p. 8; 153 (1863), p. 316. 



(12) Harris, F. I., and Hoyt, H. S., "Science," N. S., 46 (1917), p. 318. 



(13) Herlitzka, A., Zeit. f. chem. und der KoUoide, 7 (1910), p. 251. 



(14) Heubner, W., and Rosenberg, H., Biochem. Zeit., 38 (1912), p. 345. 



(15) Hopkins, F. Gowland, Journ. of Physiol., 25 (1900), p. 306. 



(16) Hoppe-Seyler, F., Virchow's Arch., 11 (1857), p. 552. 



(17) Hoppe-Seyler, F., Virchow's Arch., 33 (1862), p. 446. 



' (18) Hoppe-Seyler, F., Zeit. f. chem. und Pharm., 7 (1864), p. 737. 



(19) Hoppe-Seyler, F., Med.-Chem. Untersuch. (1867), p. 169. 



(20) Hoppe-Seyler, F., Handb. d. physiol. und pathol. Chem., 7 Aufl. Berlin 



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