EXPERIMENTAL. 99 



and other substances which had separated were extracted with hot dilute 

 ammonia and the filtered extract concentrated and cooled. On standing, a 

 little more tyrosine separated, which was added to that first obtained. No 

 more tyrosine could be isolated from the solution of the hydrolytic decom- 

 position products. All of the tyrosine which had separated was dissolved 

 in 5 per cent sulphuric acid, and phosphotungstic acid was added to the 

 solution. Only a small precipitate resulted. After removing the phospho- 

 tungstic acid with barium hydroxide, the solution was concentrated strongly 

 and allowed to cool. After standing for some time, 9.62 grams of tyrosine 

 were obtained, which is equal to 4.25 per cent of the glutenin. 



Carbon and hydrogen: 0.2922 gram substance, dried at uo, gave 0.6370 gram CO, and 



0.1634 gram H 2 0. 

 Calculated for C9H U 3 N, C 59.62, H 6.13 p. ct.; found, C 59.45. H 6.21 p. ct. 



Kutscher 1 found 2.75 per cent of tyrosine in " gluten- casein." 



HISTIDINE. 



Fifty grams of glutenin, equal to 43.39 grams dried at no, were hydro- 

 lyzed, and the arginine and histidine separated in the same way as that 

 described for gliadin (p. 81). The solution containing the histidine was 

 made up to 500 cc. 



Nitrogen: 100 cc. solution gave NH 3 =4.15 cc. HC1 (1 cc. HC1 =0.01 gram N) = 

 0.0415 gram N = 0.2075 gram in 500 cc. = 0.7645 gram histidine = 1.76 p. ct. of 

 the glutenin. 



The amount of histidine in the remaining solution was too small for 



identification. 



arginine. 



The filtrate from the histidine precipitate yielded 500 cc. of solution con- 

 taining the arginine, in which was found the following amount of nitrogen : 



Nitrogen: 50 cc. solution gave NH 3 = 6.79 cc. HC1 (1 cc. HC1 = 0.01 gram N) = 

 0.0679 gram N, or 0.679 gram in 500 cc, or 2.107 gram arginine = 4.72 p. ct. of the 

 glutenin. 



The remaining solution, treated as Kossel directs, yielded the arginine as 

 carbonate. This was converted into the copper salt, which gave the fol- 

 lowing results on analysis : 



Carbon and hydrogen: 0.2118 gram substance, air-dried, lost 0.0210 gram H 2 at ioo. 

 Calculated for C 12 H 28 O 10 N 10 Cu 3 H 2 0, H 2 9.15 p. ct. ; found, H 2 9.92 p. ct. 

 Copper : (I) 0.1858 gram substance, dried at ioo, gave 0.0275 gram CuO ; (II) 0.1808 



gram substance, dried at ioo, gave 0.0267 gram CuO. 

 Calculated for C 12 H 28 O 10 N 10 Cu, Cu 11.85 p. ct. ; found, Cu (I) 11.84, (II) 11.78 p. ct. 



1 Kutscher, Zeitschrift fur physiologische Chemie, 1903, xxxvi, p. 114. 



