CHAPTER VIII 

 THE FORMATION AND DISSOCIATION OF PROTEIN SALTS 



1. Compounds of the Proteins with Inorganic Bases and 

 Acids ; the Non-Dissociable Character of the Inorganic Radical. 

 -We have already had occasion to incidentally dwell upon the 

 fact that the inorganic radical of the protein base and protein 

 acid compounds is not electrically dissociated as such. The most 

 direct proof which we possess of this fact is that which was ob- 

 tained by Bugarszky and Liebermann (4). These observers 

 employed the potentiometric method, using two different con- 

 centration chains. The first was the ordinary gas-chain: 



the potential being measured, first with pure acid in 2 and then 

 with acid plus protein; the difference between the two readings * 

 yielding by computation from the Nernst formula, the number 

 of hydrogen ions bound by the protein. The second concentration- 

 chain was built up as follows: 



and enabled them to estimate, in a similar way, the number of Cl f 

 ions bound by the protein. Now the number of CV ions bound by 

 a given mass of protein dissolved in dilute HCl was found to be 

 exactly equal to the number of H + ions which it binds. The fol- 

 lowing data are compiled from those obtained by Bugarszky and 

 Liebermann : 



* Less a correction expressing the potential between 2 and 3. 



167 



