22 Notes from the Physiological Laboratory 



chemical method of estimating the albuminoids of 

 a given body, namely, from the entire amount of 

 nitrogen contained in it. Especially is this true in 

 the case of vegetable tissues. In a close analysis of 

 the potato, Schultze and Barbieri found that only 

 56.2 per cent, of all its nitrogen existed in albu- 

 minoid combination, while in the fodder-beet only 

 20 per cent, of the nitrogen went to the formation 

 of albuminous compounds; the remainder in each 

 case entering into the composition of non-nutritious 

 bodies, as amides, nitrates, ammonia, and asparagin. 



The fact that the gluten net- works become denser 

 toward the periphery of the endosperm, together 

 with the presence of non-albuminoid nitrogenous 

 compounds in the perisperm, explains the notable 

 percentage of nitrogen found in bran as ordinarily 

 roughly removed. 



The color-tests mentioned above indicate that the 

 amount of proteids contained in the cells of the 

 fourth layer is relatively very slight; but admitting 

 for the moment that these cells contain gluten, 

 the question naturally arises whether, in view of 

 their dense cellulose walls, they are capable of serv- 

 ing as a food-stuff for man. In artificial digestion 

 the writer has found these elements, even when 

 thoroughly cooked, to be unaffected by the digestive 



