SALTS OF ALBUMIN WITH BASES 



99 



In spite of the lack of electrometric determinations of the 

 cations, we must conclude from the results so far obtained that 

 the ionisation of the alkali protein increases progressively with 

 increase in the concentration of base until the highest value is 

 reached, which corresponds to maxi- 

 mum viscosity and minimum precipi- 

 tation by alcohol. The ionisation is 

 repressed by excess of alkali, and there 

 are thus the same differences in 

 hydration and precipitation between 

 the neutral and the ionised albumin 

 as have already been noticed in the 

 case of the acid proteins. 



In the electrophoresis apparatus, 

 the protein portion of the alkali pro- 

 tein moves towards the anode, thus 

 showing conclusively that negative 

 protein ions are produced. In excess 

 of alkali, electrometric measurements 

 show no increase in combination, 

 while there is much evidence for a 

 suppression of the ionisation of the 

 alkali protein. It is, therefore, 

 extremely probable that the metallic 

 ion of the alkali is the common ion 

 in that and in the protein salt, which, 

 according to this view, dissociates 

 into a positive metallic ion and a 

 negative protein ion. Further evi- 

 dence for this conception, which is the 



FIG. 23. 



I. Tetraethylammonium 



hydroxide. 

 II. Sodium hydroxide. 



III. Piperidine. 



IV. Diethylamine. 

 V. Ethylamine. 



VI. Methylamine. 

 VII. Trimethylamine. 



opposite of that held by T. B. Robert- V Jx! NiSS2 Um hydroxide - 



X. Pyridine. 

 XI. Ecgonine. 



son, is available, particularly from 

 the results obtained for the electrical 

 conductivity of the alkali proteins, which will be discussed later. 

 As a consequence of this conception, the possibility of precipita- 

 tion of the alkali albumin by excess of alkali has to be considered, 

 and such a precipitation has actually been noticed by R. Wagner 

 (loc. tit., p. 78) in dialysed serum albumin in high concentra- 



7-2 



