MIGRATION-VELOCITY 187 



(2) Solution of 4 per cent casein in 0.02 N KOH; neutral to litmus. 

 Electrolysis for 2 hours at 30 degrees. Current approx. 1 milliampere. 



Gram of casein lost from the anodal arm . 093 ± . 008 



Gram of casein lost from the cathodal arm . 045 ± . 007 



Ratio 2.15 ±0.55 



(3) Solution of 3.75 per cent casein in 0.03 N KOH; neutral to phenol- 



phthalein. 

 Electrolysis for 2 hours at 30 degrees. Current approx. 1 milliampere. 

 Gram of casein lost from the anodal arm . 070 ± . 008 



Gram of casein lost from the cathodal arm . 045 d= . 009 



Ratio 1.65 ±0.55 



Within the experimental error, therefore, the ratio of the anodal 

 to the cathodal loss is 2, as demanded by theory. The experi- 

 mental error in determining the ratio is, however, large, as the 

 above figures reveal, and although these results may be taken as 

 confirmatory of the general correctness of the above outline of 

 the mechanism of electrolysis in these solutions, yet they do not 

 suffice to enable us to determine whether or not the protein anions 

 and cations are absolutely equal in mass. Further elaboration 

 and refinement in the technique of these measurements will 

 doubtless enable us in the future, however, to measure the rela- 

 tive masses of the protein anions and cations with considerable 

 precision. 



In passing it may be pointed out that these results afford a 

 striking confirmation of the view which I have developed above 

 that the protein salts in solution in water do not yield protein 

 and inorganic ions but only protein ions. Referring to the 

 Hittorf diagram again it will be evident that if the cations 

 were potassium ions the loss of casein from the anodal region 

 should be at least four times that from the cathodal region, since 

 the equivalent velocity of potassium ions is at least four times 

 that of heavy organic ions. The experimental fact that the loss 

 from the anodal region is only about twice as great as that from 

 the cathodal region can only be interpreted by assuming that 

 protein material is transported into the cathodal region by the 

 current, in other words, that the current is transported in both direc- 

 tions hy protein ions. 



4. The Migration- Velocity of Protein Ions. — W. B. Hardy 

 endeavored to measure the migration-velocities of serum-globu- 

 lin ions directly (10) by placing solutions of serum-globulin, 

 combined with acids or bases, at the bottom of a U-tube and 



