[macfarlane] 



CONSTITUENTS OF GLUTEN 



21 



percentages which, in all methods of detennining gliadin by direct ex- 

 traction of the flour with alcohol, would increase the amount of gliadin 

 given in column 6. In column 11 some cases appear which show an 

 overplus of proteids in the products from the flour, which may be due 

 to experimental error. In other cases there is a considerable deficiency 

 which is possibly attributable to mechanical loss of gluten in washing 

 out the starch. It is difficult to say what the substances may be which 

 are classed as " dextrinoids " (7). That there are present in the 

 gluten special non-nitrogenous substances insoluble in the water used 

 for producing the gluten and soluble in 70 per cent alcohol is proved 

 by the consideration that, even if the old factor 6.25 were used to calcu- 

 late proteids from the nitrogen, the loss sustained in the extraction 

 with alcohol would not be made up. If the nitrogen in the alcoholic 

 solution is reckoned as a percentage on the loss sustained 'that percentage 

 never reaches 16, the amount generally supposed to be present in proteids. 



The differences shown by the above analyses are reproduced in the 

 following table, but in such a manner as to bring out the essential 

 variations among the samples : — 



