HENDERSON, COHN, CATHCART, WACHMAN, AND FENN 469 



TABLE VII — Concluded. 



V. 



Finally, we have measured the viscosity of swollen gluten with the 

 help of the viscosimeter previously described. In every case 12 gm. 

 of the swollen gluten were introduced into the apparatus.^ The re- 

 sults of these measurements are included in Table VIII. 



It should be understood that these measurements are of very mod- 

 erate accuracy which, nevertheless, is sufficient for the present pur- 

 pose. Evidently there is a well marked minimum of viscosity near a 

 hydrogen ion concentration corresponding to pH 5.7. This minimum, 

 as will be shown in a later paper, while due chiefly to the hydrogen 

 ion concentration, is in a secondary manner influenced by the amount 

 of electrolyte present in the system, and varies with this factor as well 

 as with the acidity. The electrolyte concentration determines the 

 great variation in viscosity measurements in the systems where the pro- 

 tein is suspended in distilled water. It will be shown in a later paper 

 that the value of 3.0 for the system containing 8 gm. of gluten is 

 most nearly comparable with the other data of the table. 



3 Henderson, L. J., Fenn, W. 0., and Cohn, E. J., J .Gen.Physiol.,\9\S-\9,\, 387. 



