1883.] NATURAL SCIENCES OF PHILADELPHIA. 311 



within the grain fully as accurate as that given by the usual 

 chemical method of estimating the albumenoicls 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 562 

 per cent, of all its nitrogen existed in albnraenoid combination, 

 while in the fodder-beet only 20 per cent, of the nitrogen went to 

 the formation of albumenous compounds; the remainder in each 

 case entering into the composition of non-nutritious bodies, as 

 amides, nitrates, ammonia and sxs\ aragin. 



The fact that the gluten networks become denser toward the 

 peripher}' of the endosperm, together with the presence of non- 

 albumenoid nitrogenous compounds in the perisperni, 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 serving as a food-stuff 

 for man. In artificial digestions the writer has found these 

 elements, even when thoroughly cooked, to be unaffected by the 

 digestive juices ; that is, well-boiled bran with its adherent "gluten- 

 cells,'' will sustain prolonged maceration at the temperature of 

 the human digestive tract in artificial gastric and pancreatic juice 

 (in which, under the same conditions, fibrin is readily digested) 

 without exhibiting any change. These cells were further found 

 to be unaffected bj' maceration for thirty days in liquor potassai, 

 except for a slight swelling of the cell and the occasional coales- 

 cence ,of some of its contained oil-globules. They were also 

 practicall}' unchanged b}^ a few daj's' immersion in strong nitric 

 acid. In order to obtain conclusive and unassailable results as to 

 the nutritive value of the " gluten-cells " as far as man is con- 

 cerned, the writer has at present under observation a number of 

 healthy adults, who daily receive, in addition to their regular diet, 

 a small fixed amount of boiled bran. Their alvine dejections 

 (containing all the undigested elements of food after the normal 

 act'on of all the digestive juices) will be submitted to close micro- 

 scopical examination, with a view to ascertaining the extent to 

 which the "gluten-cells" have been digested, and a report will 

 be made upon the results in the near future. 



