INTERPRETATION 



265 



to 60 per cent of alcohol, we may conclude that in these solu- 

 tions it is for the greater part the migration-velocity of the 

 caseinate ions which is affected by the percentage of alcohol 

 in the solvent. From the values of the constants in equations 

 (iii) to (ix) it is apparent that the migration-velocities of the 

 casein-ions are progressively diminished by increasing alcohol- 

 concentration from to 60 per cent. From the facts that the 



law x v = ~ no longer holds good for the solutions containing 



Ay 



75 per cent alcohol and the ratio ^*_ i s no t constant we may 



Zalc.H,O 



conclude that in these solutions the degree of dissociation of the 

 caseinate or the number of equivalents of casein produced by 

 one equivalent of KOH or both undergo a profound modification. 

 The values of the constants in equation (x) indicate an increase 

 in the magnitude of u + v and a very great decrease in the mag- 

 nitude of the dissociation-constant. In the following table the 



Tr 



values of p (u + v) and of corresponding to the equations (iii) 



$ P 



to (x) are enumerated; in the fourth column is given the per- 

 centage dissociation of the caseinate in the solutions containing 

 0.025 N KOH bound by casein (at 30 degrees). 



TABLE IX 



Potassium Caseinate. 80X10" 5 Equivalents of KOH per gram 



The degree of dissociation of the caseinate in the solutions con- 

 taining 60 per cent and less than 60 per cent of alcohol is evidently 

 but little affected by the percentage of alcohol in the solvent, the major 

 part of the effect of the alcohol upon the conductivity being attri- 

 butable to the decreased mobility of the caseinate ions. 



