12 



Scientific Proceedings (30). 



condition. The proportions otherwise were not greatly different 

 from those found in fibrin. It is evident that the plastein ranks 

 with either the complex native proteins or their higher decompo- 

 sition products. 



In order to obtain evidence indicating with which of the above 

 classes the plastein is to be ranked, viscosity measurements were 

 employed. It has been shown that digestion of a protein solu- 

 tion is accompanied by a rapid decrease in viscosity. Conse- 

 quently it appears that, under similar conditions, even its primary 

 decomposition products form markedly less viscous solutions than 

 the mother protein. 



On comparison of equally concentrated solutions of plastein 

 and fibrin in normal NaOH (400 mg. of diy substance to 10 c.c. 

 solvent), it was found that the plastein solution showed much the 

 lower viscosity. The fibrin was gradually hydrolyzed by the 

 alkali, however, and the viscosity of its solution fell finally even 

 below that of the plastein, which had changed but little. 



For further comparison, viscosity measurements were per- 

 formed upon similar solutions of hetero-albumose, and of the 

 proteins casein, gliadin, glutein and edestine. The hetero-albu- 

 mose gave a solution of viscosity similar to that of the plastein, 

 while the native proteins all showed, like fibrin, markedly higher 

 viscosities, and also less stability in the presence of alkali. 



These results indicate that the plastein is related to the higher 

 albumoses, and apparently, from its resistance to alkali, to the 

 anti-albumoses rather than to the native proteins. 



For the determinations, the proteins were dissolved by shaking 

 on a machine at room temperature. All solutions were clear ex- 

 cept that of glutein, which was cloudy. The viscosity of each 

 was determined as soon as solution became complete, and the 

 determination repeated at intervals. The time intervals were not 

 regular, but figures for roughly comparable intervals are tabulated 

 on the same line. The figures under " Hrs." indicate the time in 

 hours between the mixing of substance and alkali, and the vis- 

 cosity determination opposite. The viscosity figures indicate the 

 rate of flow of the solutions through an Ostwald viscosimeter at 

 23° ± 0.1°, the rate of flow of water at the same temperature be- 

 ing taken as 100. 



