MIGRATION VELOCITY OF THE PROTEIN IONS 131 



Circuit II. 



Hg/HgCl . N KCl/o-002 N HC1 -f- i per cent. alb./KCl cone./ 



0-002 NHC1/N KC1 . HgCl/Hg. 

 T =293 

 EI. = 0-025 v lt. 

 E n . = 0-059 volt. 

 Diffusion potential = E IIt E It 0-0322 + 0-0005 volt. 



A careful analysis showed that the albumin solution contained 

 ammonium sulphate in a concentration of 0-0046 N, owing to 

 the purification of the albumin by the precipitation method. 

 Hence Cso 4 = C NH4 = 46 X io~ 5 . The hydrion concentration 



2 



in the albumin HC1 mixture was 5-4 x io~ 5 N, and the 

 concentration of chlorine ions 170 X io~ 5 N. In the solution 

 of pure hydrochloric acid C H = C a = 170 X io~ 5 N. Thus 

 combination of hydrion with the albumin accounts for the 

 difference, 164 x io~ 5 N, in the hydrion concentration ; and 

 this is equal to the normality of the albumin salt. Also, 



^H = 330, V C l = 68, V S o 4 = 71, NH 4 = 67. 



These various values were then substituted in Henderson's 

 equation, which was then solved for U Alb . The value obtained 

 is 5 8, if it is assumed that the albumin ion is monovalent in 

 this low concentration of acid. This result, as far as order of 

 magnitude is concerned, is in satisfactory agreement with that 

 obtained by Pauli and Oden for the mobility in low concentra- 

 tions of acid. The determination of migration velocity by the 

 method of diffusion potentials has proved in practice to be a 

 somewhat complicated matter and not at all sensitive ; but 

 such methods have a special importance in elucidating the 

 origin of the bio-electric current. 



The behaviour of salts of the proteins on electrolysis is closely 

 connected with the valency of the protein ions. As we now 

 know that proteins form typical metallic salts with alkalis, we 

 should expect that when alkali proteins are electrolysed the 

 metallic ion would appear at the cathode, and the protein ion 

 at the anode. The former ions react with the water with 

 formation of the original alkali, the latter in the case of a protein 



9-2 



