1902-3.] The Chemistry of Wheat Gluten. 5^5 



in the Soxhlet apparatus for ten hours with absolute alcohol, and dried 

 for three hours at 1 10 X., the glutenin so prepared gave on analysis the 

 following : — 



GLUTENIN. 



Nasmith. Osborne. 



C 52 -75 52-34 



H 7.22 6.83 



N 16.15 17 49 



S 1 . 06 1 . 08 



O 22.58 22.26 



P 0.215 



Fe 0.026 . 



100.00 100.00 



Ash 0.188 per cent. 



Another preparation by Fleurent's method^' which was also care- 

 fully filtered, yielded 16.55 P^f cent, nitrogen. The figures are not at 

 all in agreement with those of Osborne and Voorhees for this compound. 

 Mine are considerably higher in carbon and hydrogen, and much lower 

 in nitrogen, a result which might be accounted for by carbohydrate 

 impurity. Since, however, it was prepared exactly as described by him 

 this seems unlikely. The fact that the amount of iron and phosphorus 

 is practically the same as in gliadin at once suggested the possibility of 

 these elements being derived from a certain amount of nuclein mechani- 

 cally carried along with these compounds in the attempted purification 

 process. 



Impure glutenin was digested with pepsin and hydrochloric acid, 

 but the insoluble residue was so difficult to separate from soluble starch, 

 and was so evidently impure that the complete analysis was not made, 

 though the presence of iron and phosphorus in it was demonstrated. 



In repeating the work of Morishima^^ a copious precipitate as usual 

 occurred at the neutral point, but when more acid was added nearly all 

 went into solution ; after twenty-four hours only a trace of precipitate 

 settled out. Glutenin has again and again been shown to be soluble m 

 dilute acids. Artolin, as I found, is derived from another source than 

 Morishima supposed. A 0.4 per cent, hydrochloric acid extract of flour 

 was made, filtered perfectly clear and potassic hydrate added until 

 neutral, when a precipitate was thrown down, which proved to be nearly 

 all gliadin. If to this 0.4 per cent, hy^drochloric acid extract more acid 

 was added, a precipitate began to appear which increased with the 

 acidity. This in large part separated on heating, and it proved entirely 

 soluble in 70-80 per cent, alcohol, the result showing it to be gliadin. 



