96 COLLOID CHEMISTRY OF THE PROTEINS 



combined, useful information on the dissociation of the protein 

 salts. 



Of these, the determinations of viscosity and of degree of 

 precipitation by alcohol made by C. Schorr * on alkali-albumin 

 will be considered first. The variation of these properties 

 with time, which has been studied in other experiments, is 

 allowed for by careful extrapolation of the original viscosity 

 and by determining the quantity precipitated by alcohol 

 immediately after the mixture was made up. In the following 

 table the data obtained by Schorr are corrected in the light of 

 recent electrometric measurements which allow for the viscosity 

 due to the uncombined alkali. This slight alteration in the 

 actual values does not, however, affect his general facts or the 

 conclusions drawn from them. 



Table 43. 



Ox-serum Albumin free from Salts (1*15 per cent.) 

 Relative Viscosity rj at 25. 



These results, and those of similar experiments, show that 

 that fraction of the viscosity of the alkali albumin which is due 

 to the albumin passes through a maximum as the concentration 

 of alkali is increased, and then, with further addition of alkali, 

 falls off in value. With the more concentrated albumin 

 solution quoted above, the maximum value is obtained in 

 alkali of 0-05 N concentration. 



Glutin also shows a maximum in viscosity, which occurs in 

 still lower concentrations of alkali, and, owing to the high 

 viscosity of the glutin solutions, the correction for viscosity of 

 * Biochem. Zeitsch., 1912, 47, 269. 



