1902-3.] The Chemistry of Wheat Gluten. 499 



dilute alcohol or hot water, which gave the reddish violet reaction of 

 proteoses and peptones. Because of this reaction and its comparative 

 insolubility he called it insoluble phytalbumose. The residue was 

 coagulated by boiling water, and was soluble only in acids and alkalies. 

 He claimed that dilute alcohol extracted only fat from dry flour, and 

 came to the conclusion that insoluble phytalbumose was produced from 

 a soluble albumose, and gluten fibrin from a globulin by pre-existing 

 ferments. 



Chittenden and Smith'^ made preparations of gluten casein accord- 

 ing to Ritthausen's method, which averaged 15.86 per cent, of nitrogen. 



Osborne and Voorhees^^ in an exhaustive research brought many 

 opposing views into harmony. Like Martin they found only one 

 proteid in gluten that was soluble in alcohol, and considered that the 

 various proteids claimed by previous investigators to have been soluble 

 in alcohol were impure preparations, perhaps mixtures with fat. Martin's 

 gluten fibrin they termed glutenin, and found its composition to be 

 practically identical with that of gliadin, a conclusion that had not 

 hitherto been suggested. The high percentage of nitrogen they thought 

 due to their improved method of preparation by which all starch, etc., 

 had been removed. Contrary to Martin's experience they found that 

 dilute alcohol extracted gliadin directly from flour. 



Osborne and Voorhees further arrived at the conclusion that gluten 

 is made up of two forms of the same proteid, one being soluble in cold 

 dilute alcohol and the other not. They found that flour exhausted with 

 sodium chloride solution yielded the same amount of gliadin as was 

 obtained from the gluten made from an equal quantity of flour, or by 

 direct extraction of the flour with 70 per cent, alcohol. They, therefore, 

 held that gliadin exists as such in the seed. 



Teller^^ noted again the fact that gliadin possessed proteose-like 

 characters, as previously stated by Martin, Gliadin he found to be 

 slightly soluble in dilute salt solution, and he regarded it as identical 

 with that body classified by Osborne and Voorhees as proteose. 



O'Brien^" found himself in agreement with Osborne and Voorhees 

 in considering that gluten pre-existed as such in flour in the same 

 proportions as in gluten, and that there was but one mother substance in 

 flour which gave rise by a process of hydration to gluten. His con- 

 clusions were, {a) that the differently described derivatives of gluten 

 soluble in alcohol merge into one another ; {b) that the portion soluble 

 in alcohol may be made to pass into the insoluble stage ; {c) that a 

 proteose is readily formed as a secondary product from gluten. 



