EXPERIMENTAL. 63 



One kilogram of whole spring- wheat flour, freshly ground, was made into a 

 dough, and the gluten obtained from this by washing with water was then 

 chopped fine and thoroughly extracted with alcohol of 0.90 sp. gr., the 

 yellow extract concentrated, and the protein separated by cooling. The 

 deposit thus produced was dissolved as far as possible in dilute alcohol, and 

 the insoluble substance, which was coagulated protein, was washed with 

 dilute alcohol, absolute alcohol, and ether. This was preparation 83. 



The solution filtered from 83 was poured into absolute alcohol and a small 

 amount of protein separated ; this was treated with absolute alcohol and 

 ether in the usual way, yielding preparation 84. The filtrate from 84 was 

 concentrated to small volume and poured into absolute alcohol, whereby 

 nearly all the protein was precipitated. This substance was dehydrated with 

 absolute alcohol and digested with ether, giving preparation 85. These three 

 bodies had the composition shown by the figures for preparations 83, 84, 

 and 85 in the table on page 62. 



In a similar manner an extract was made of winter-wheat meal obtained 

 by grinding the entire wheat kernel in the laboratory, the alcoholic extract 

 concentrated to about one-third of its volume, cooled, and the solution 

 decanted from the deposit. This was then dissolved in alcohol of 0.90 

 specific gravity and the coagulated protein filtered off, washed with dilute 

 alcohol, digested with absolute alcohol and then with ether, giving prepara- 

 tion 86. 



The solution filtered from this preparation was concentrated to small 

 volume, cooled, and the protein separated was digested with absolute alcohol 

 and with ether, yielding preparation 87. (See table on p. 62. ) The complete 

 extraction of this protein from the gluten is very difficult, a little generally 

 remaining in the insoluble residue after extracting with dilute alcohol. In 

 one case the residue thus remaining was dissolved in o. 2 per cent potassium- 

 hydroxide solution, and the resulting solution, after standing some time to 

 deposit suspended impurities, was decanted and precipitated with dilute 

 hydrochloric acid. This precipitate was washed by decantation with water 

 and then digested for some time with dilute alcohol. The alcoholic solution 

 was then filtered and concentrated to small volume and cooled. The protein 

 separated was then digested with absolute alcohol and with ether and dried 

 at 1 10 for analysis. 



From this analysis it is seen that the protein soluble in dilute alcohol is 

 not changed in composition by solution with potassium hydroxide, nor is its 

 solubility altered, so far as could be learned. 



In order to facilitate a comparison of these analyses they have been 

 brought together in table 15. 



