4 6 



THE PROPERTIES OF PROTEINS 



to iso-electric effects. This change point can also be demon- 

 strated in the electrophoresis apparatus. For glutin the con- 

 centration of added acid which produces this effect lies between 

 7 X io- 5 and 10 x io~ 5 N/i HC1. The following table gives 

 some collected results for glutin B. 



Table 15. 

 Electrophoresis of Glutin (i per cent.). 



(75 volts for one hour at 35.) 



N . HCI. 



o 



2-5 X TO- 5 



5 X io- 6 



7-5 X IO- 5 



io x io- 5 



Migration. 



To anode. 



To cathode. 



For the same sample of glutin the maximum number of 

 neutral particles occurs in i X io- 3 N.HC1. 



Table 16. 

 Precipitation and Viscosity of 0*5 per cent. Glutin. 



At the point of iso-electric migration the chlorion concentra- 

 tion is certainly from 7 io X io~ 5 N. This is only a mini- 

 mum value, in view of the possibility of slight diffusion into the 

 albumin from the acid of the same dilution which lies above it 

 in the electrophoresis apparatus. In this protein-acid mixture 

 the hydrion concentration is at most io~ 6 N. In any case 



