May 20, 1918 



Hydration Capacity of Gluten 



413 



Table X. — Concentration of the lactic and acetic acids at the maximum point on the 



various imbibition curves 



Solution. 



Acid alone Njio 



Acid+potassiura chlorid NI5 



Acid+potassium phosphate. . > NI2 



Acid+potassium tartrate >■ NI2 



Acid+calcium chlorid Nj^ 



Acid+magnesium sulphate.. Nj^ 



Acid-j-mercuric chlorid !<^ NI500 



Acid-|-aluminium sulphate. . .|> NI2 



Lactic acid. 



NJ25 



Njio 



Nl5 



Nl5 

 >Nl2 



NI5 

 < NI500 

 >Nl2 



Nlio 



NI5 



Nlio 



NI5 

 >Nl2 

 >Nl2 

 < NI500 

 >Nl2 



Acetic acid. 



Nl5 



>Nl2 



Nl5 

 >Nl2 



Nlio 

 Nlio 

 >Nl2 

 >Nl2 



Nlio 

 >Nl2 



>Nl2 

 >Nl2 



The imbibition curves in the presence of lactic acid plus mercuric 

 chlorid are the reverse form from the curves in the presence of the other 

 salts. Here maximum imbibition takes place in the 0.005 molar solution 

 of mercuric chlorid, and when acid is added, the imbibition rapidly 

 decreases. The more inferior the gluten the lower is this minimum 

 imbibition. When, however, the lactic acid is replaced by hydrochloric 

 acid, maximum imbibition does not take place in the 0.005 molar solution 

 of mercuric chlorid alone, but in solutions containing both the mercuric 

 chlorid and hydrochloric acid. The imbibition curves here are com- 

 parable in form to those for the other salts. Just what factors cause 

 this reversal of form of the curves in the two instances is uncertain, and 

 the subject was not further investigated, inasmuch as it was thought 

 to be of more theoretical than of practical interest. 



Table XI. — Average iinbibiiion of the different glutens in the various solutions of acids 



and of acids plus salts 



' The figures on AVi and Wa glutens were, respectively; Lactic acid alone, 0.65 and 0.49; acetic acid alone, 

 0.32 and 0.48; oxalic acid alone, 0.38 and 0.39; and hydrochloric acid alone, 0.30 and 0.31. 



Table XI shows the average imbibition of the different glutens in the 

 different acids and salts. Each of these figures represents the average 

 point of an entire curve, and as such represents from 24 to 56 individual 

 determinations of the weight of water imbibed. The averages of such 

 a large number of determinations certainly ought to have significance. 



