48 



THE PROTEINS OF THE WHEAT KERNEL. 



The gumm)' precipitate, having the general appearance and properties of 

 similar precipitates of the proteoses obtained by the action of pepsin, was 

 dissolved in water, dialyzed free from sulphates, and then precipitated by 

 dialysis in alcohol, giving 2 grams of preparation 51. These preparations 

 were dried at no and analyzed with the results shown in table 10. 



From these analyses it is seen that the matter insoluble in water, forming 

 preparations 42, 45, and 48, consists of coagulated protein apparently mostly 

 derived from leucosin. The high proportion of sulphur in 42 and 45 is due 

 to calcium sulphate precipitated by alcohol from the aqueous extract. The 

 remaining preparations have the low percentage of carbon characteristic of 

 proteoses made by pepsin digestion. 



THE PROPORTIONS OF THE VARIOUS PROTEIN SUBSTANCES OF 



THE WHEAT EMBRYO. 



Twenty grams of fresh germ meal, from which the ether-soluble constit- 

 uents had not been separated, were treated with 500 cc. of water, and after 

 shaking for some time the extract was filtered clear. Two portions of 100 

 cc. each were treated with a few drops of very dilute hydrochloric acid and 

 heated in a boiling water-bath. The coagulum which separated was col- 

 lected on a filter and its nitrogen determined. To the filtrate from one 

 coagulum tannin was added, and nitrogen was determined both in the pre- 

 cipitate and in the filtrate. Another lot of 20 grams was treated in the same 

 way and nitrogen determined in the heat-coagulum formed in each of two 

 portions of 100 cc. The amount of nitrogen corresponding to 1 gram of 

 germ meal was found in the four coagula to be 0.0163 gram, 0.0156 gram, 

 0.0159 gram, and 0.0162 gram, in the tannin precipitate 0.0062 gram, and in 

 the solution filtered from the latter 0.0062 gram. 



