EXPERIMENTAL. 8 1 



solutions from which the tyrosine separated still continued to give a strong 

 Millon's reaction. Kutscher 1 found 2.09 per cent of tyrosine in gliadin, 

 and Abderhalden & Samuely 2 found 2.37 per cent. 



HISTIDINE. 



Fifty grams of gliadin, equal to 43.97 grams dried at 1 10, were hydrolyzed 

 according to the directions of Kossel & Kutscher 3 and the determination 

 of the bases carried out according to the method of Kossel & Patten.* 



The solution of the histidine was made up to 500 cc. and nitrogen deter- 

 mined in 100 cc. of it. 



100 cc. of solution gave ammonia = 1.37 cc. HC1 (i cc. HC1 = o.oi gram N) = 0.0137 

 gram N = 0.0685 gram N in 500 cc. = 0.2524 gram histidine = 0.58 p. ct. of the 

 gliadin. 



The identity of this histidine was not established, as the quantity was too 

 small to permit the preparation of a satisfactory product. 



ARGININE. 



The arginine solution was made up to 500 cc. and nitrogen determined in 

 50 cc. of it. 



50 cc. of solution gave ammonia=4.i5 cc. HC1 (i cc. HCl=o.oi gram N) =0.0415 

 gram N or 0.415 gram in 500 cc. = 1.39 gram arginine or 3.16 p. ct. of the gliadin. 



The remaining solution was treated as Kossel & Kutscher direct and the 

 arginine obtained as carbonate. A portion of this carbonate was converted 

 into the picrolonate according to the directions of Steudel. 5 This melted at 

 226 to 227, while Steudel gives 225. 



Nitrogen: 0.0832 gram substance, dried at 110, gave 18.8 cc. moist N 2 at 765 mm. 



and 25. 

 Calculated for C 6 H U O 2 N 4 C 10 H 8 O 5 N 4 , N 25.62 p. ct.; found, N 25.40 p. ct. 



The filtrate from the silver precipitate of arginine and histidine was freed 

 from silver, precipitated with phosphotungstic acid, and lysine tested for 

 with picric acid in the usual way, but none was found. 



Kossel & Kutscher 6 found, in the three- fractions of the alcohol-soluble 

 protein of the wheat kernel which they examined, 1.2, 0.43, and 1.53 per 

 cent of histidine . The writer' s determination falls between these . Kutscher, 7 

 in discussing the individuality of these three fractions, considers the differ- 



1 Kutscher, Zeitschrift fur physiologische Chemie, 1903, xxxvm, p. in. 



2 Abderhalden & Samuely, ibid., 1905, XLIV, p. 276. 



3 Kossel & Kutscher, ibid., 1900, xxxi, p. 165. 



4 Kossel & Patten, ibid., 1903, xxxvm, p. 39. 



5 Steudel, ibid., 1902, xxxvu, p. 219. 



6 Kossel & Kutscher, loc. cit. 



7 Kutscher, loc. cit. 



6 



