x THE NUCLEIC ACIDS 441 



Steudel 26 has decomposed thy mus- nucleic acid by means of 

 hydriodic acid in the presence of phosphoric acid, and has succeeded 

 in accounting for 75 per cent of the total nitrogen. He gives, with 

 all reserve, the following tabular statement : 



Thymin and Uracil . . . . 15 '88 



Adenin . . . . . 13 '45 



Humin-nitrogen . . . . 11 '54 



Cytosin . . . . . .11-45 



Ammonia / . . . . 7 '00 



Xanthin . . . . . ."674 



Hypoxanthin . . . . 5 '20 



Guanin 3*61 



74 -87 per cent. 



Some of the dissociation-products, especially purin-bases, have also 

 been found in a large number of organs ; Kossel 27 found all the bases 

 which he by then (1882) had discovered in the spleen, kidney, liver, 

 testes, brain, blood, and muscle, and especially large quantities in 

 leucsemic blood and in embryonic muscle. Pekelharing 28 found 

 xanthin in the nucleo-proteid of the gastric juice ; Inoko, 29 working 

 under Kossel, adenin in the red blood-corpuscles of geese ; Kossel and 

 Neumann, 30 thymin in the milk ; Grund, 31 pentoses in the pancreas, 

 liver, thymus, thyroid, salivary gland, spleen, brain, and muscle ; 

 Araki, 32 Isevulinic acid in a nucleic acid prepared from the intestinal 

 mucous membrane ; Hammarsten, 33 a carbohydrate in the mammary 

 gland. 



A large number of nucleic acids and their dissociation-products 

 have been described by Levene. 34 



A definite picture of the constitution of nucleic acids we cannot 

 as yet draw from the known data, especially because quantitative 



20 A. Kossel and H. Steudel, Zeitschr. f. physiol. Chem. 37. 377 (1903). 



21 A. Kossel and H. Steudel, ibid. 38. 49 (1903). 



22 A. Neumann, Arch. f. (Anat. u.} Physiol. 1899, Suppl. p. 552. 



23 F. Miescher and 0. Schmiedeberg, Arch. f. experiment. Path, und Pharm. 37. 

 1 (1896). 



. 24 T. B. Osborne and J. F. Harris, Zeitschr. f. physiol. Chem. 36. 85 (1902). 



25 H. L. Wheeler and T. B. Johnson, Amer. Chem. Journ. 29. 505 (from the abstract 

 in the Chem. Centr. 1903, I. p. 1311). 



2C H. Steudel, Zeitschr. f. physiol. Chem. 42. 165 (1904). 



27 A. Kossel, ibid. 7. 7 (1882). 



28 C. A. Pekelharing, ibid. 35. 8 (1902). 



29 Y. Inoko, ibid. 18. 57 (1893). so See footnote 5, p. 440. 



31 G. Grund, 35. Ill (1902). 32 T> ^^ M> 3Q 9g ^903^ 



3:5 0. Hammarsten, ibid. 19. 19 (1893). 



34 P. A. Levene, ibid. 32. 541 (1901); 37. 402 (1903); 38. 80 (1903); 39. 4 

 and 133 (1903). 



