of the University of Pennsylvania. 19 



of mercury (Millon's reagent), when the fibrils will 

 assume the bright pink tint characteristic of albu- 

 minoids under this treatment. The results of the 

 application of the xanthoproteic and biuret re- 

 actions are equally conclusive, but .more care is re- 

 quired in the use of these proteid tests, and the 

 resultant differentiation is not so clear. Reticuli 

 similar to those above described, but much broken 

 and smaller, may be seen, upon close examination, 

 scattered throughout fine white flour, without the 

 addition of any reagent. 



By general consent, the albuminoids of the wheat- 

 grain are grouped together as gluten, which is, how- 

 ever, further separable into gluten-fibrin, gliadin, 

 and mucedin, proteid bodies practically equal in 

 nutritive value, but differing in certain physical 

 properties, notably that of solubility. It must, 

 therefore, be borne in mind that in this, as in all 

 other methods of separating gluten from the other 

 constituents of the grain, its relatively small soluble 

 portion is removed with the starch, and that any 

 estimate of the quantity of gluten based upon such 

 methods will probably be rather under than over 

 the actual amount. 



2. In even the thinnest sections of the wheat-grain, 

 the gluten of the central portion is always masked 



