438 CHEMISTRY OF THE PROTEIDS CHAP. 



purin-bases into uric acid, and which then decomposes the uric acid, 

 while in the absence of oxygen neither a formation nor a decomposi- 

 tion of uric acid takes place. 



How urea is split up by the Bacillus acidi urici (Ulpiani, 1903) has 

 been studied by Ulpiani and Cingolani. 1 



4. Pentoses 



They were discovered by Kossel 2 in nucleic acid, and have also 

 been found regularly by Hammarsten 3 and Bang. 4 Neuberg 5 has 

 shown that the pentose of the pancreas-nucleic acid and also that of 

 the liver is 1-xylose. 6 The other pentoses have not yet been 

 investigated. 



5. Lcevulinic Add 



Leevulinic acid, CH 3 . CO . CH 2 . CH 2 . COOH, was discovered by 

 Kossel 7 in the nucleic acid of the thymus, and more thoroughly 

 investigated by Kossel and Neumann. 8 Noll, 9 working under Kossel, 

 found it in the nucleic acid of the spermatozoa of the sturgeon, and 

 Araki 10 in the nucleic acid of the intestinal mucous membrane. 

 Levene failed at first (see below) to get it from the nucleic acids of 

 the spleen n and of the ox-testis 12 when he used his own method of 

 preparing nucleic acids and when he tested with the phenyl-hydrazin- 

 test, but Inouye, 13 ,using Neumann's method, obtained it from the 

 nucleic acids of the ox-spleen and ox-testis, and from the spermatozoa 

 of Mursenoesox cinereus, for he got 



1. A yellow precipitate on adding iodine-potassium iodide and 



caustic soda. 



2. A red colour with sodium-nitro-prusside and caustic 



soda, and a conversion of the red into a violet colour on 

 adding acetic acid. 



1 F. C. Ulpiani and M. Cingolani, Gazetta chimica italiana, 34. 377 (1904). 

 Abstract in ZentralU.f. PhysioL 19. 166 (1905). 



2 A. Kossel, Arch./. (Anat. u.} PhysioL 1891, p. 181 ; 1893, p. 157 (Verhandlungen 

 der physioL Gesellschaft). 



3 0.. Hammarsten, Zeitschr. f. physioL Chem. 19. 19 (1893). 



4 J. Bang, ibid. 26. 133 (1898) ; 31. 411 (1900). 



5 C. Neuberg, Ber. d. deutsch. chem. Ges. 35. II. 1467 (1902). 



6 J. Wohlgemuth, Zeitschr. f. physioL Chem. 37. 475 (1903). 



7 A. Kossel, Arch.f. (Anat. u.) PhysioL 1893, p. 157. 



8 A. Kossel and A. Neumann, Ber. d. deutsch. chem. Ges. 27. II. 2215 (1894). 



9 Noll, Zeitschr. f. physioL them. 25. 430 (1898). 



10 Araki, ibid. 38. 98 (1903). 



11 P. A. Levene, ibid. 37. 402 (1903). 



12 Levene, ibid. 39. 479 (1903). 



13 P. A. Katsuji Inouye, ibid. 42. 116 (1904). 



