464 ACTION OF ACID AND ALKALI ON GLUTEN 



in any other way proportional to the quantity of combined acid. This 

 value may then be subtracted from the corrected salt conductivity, 

 thus giving as a final result that increment of the increase of conduc- 

 tivity which is not proportional to simple chemical action and which 

 measures either the inaccuracies of the assumptions and approxima- 

 tions or the changes in the systems which are not due to phenomena 

 already considered. The results of this calculation are given under 

 X in Table II. 



That part of the increase in conductivity which is proportional to 

 protein salt formation may be supposed to result from the direct 

 hberation of electrolytes by the union of the acid with the protein plus 

 at least a moiety of the ionization of dissolved protein chloride. 



The most obvious effects which have been neglected are the in- 

 creasing rate of change of solubihty of protein with increasing acidity 

 and a corresponding change in the gluten mass, which involves the 

 liberation of electrolytes. Both these factors ought to produce such 

 a change in conductivity as is revealed by the data. For tlie protein 

 which dissolves, whether chloride or not, will carry ions with it into 

 the solution, and the disintegration of the gluten will favor the escape 

 of electrolytes which might not otherwise find an open path into the 

 aqueous phase. 



It is therefore apparent that the simplest possible chemical phenom- 

 ena, which are certainly all involved in the equilibria of the system, 

 are quantitatively sufficient, v>rithin the range of accuracy of the meas- 

 urements, to explain all the data. In short, the theoretical assump- 

 tions which are necessary upon purely chemical grounds are, within 

 a very close approximation, also sufficient to account for the 

 phenomena. 



III. 



In order to proceed a step further in the investigation, it is neces- 

 sary to study the relation between electrolytes in the solution and in 

 the gluten phase. The following experiment bears upon this point. 

 A series of systems, consisting of different quantities of powdered glu- 

 ten and 100 cc. of distilled water of specific conductivity 9.6, was al- 

 lowed to stand at a temperature of 22°C., and from time to time the 

 conductivity was measured. The results are included in Table IV. 



