440 



CHEMISTRY OF THE PROTEIDS 



CHAP. 



General Properties of Nucleic' Acids 



The number of purin-bases in one molecule of nucleic acid is not 

 known. It is possible that four nucleic acids occur naturally, and 

 that each contains only one base, and that these four acids occur 

 mixed in different proportions 1 in different tissues, but it is also 

 possible that a nucleic acid may contain, for example, adenin and 

 guanin. 2 The same holds good of the pyrimidin-derivatives. The 

 transformation of purin-bases into one another is dealt with on p. 446. 

 At present it is only possible to enumerate the occurrence of the 

 dissociation-products of each individual organ. The phosphoric acid, 

 which is always found, and the pentose, which as a rule is present, 

 are not given in the table below. 



The substances not indicated in the following tables need not 

 therefore be absent in the nucleic acids mentioned ; in the most cases 

 the substances not tabulated have not been specially looked for. 



1 A. Kossel and A. Neumann, Zeitschr.f. physiol. Chem. 22. 74 (1896). 



2 0. Schmiedeberg, Schmiedeberg's Archiv f. experiment. Path. u. Pharmak. 43. 

 57 (1899). 3 A. Noll, Zeitschr.f. physiol. Chem. 25. 430 (1898). 



4 A. Kossel and A. Neumann, Ber. d. deutsch. chem. Ges. 26. III. 2753 (1893). 



5 Kossel and Neumann, ibid. 27. II. 2215 (1894). 



6 Yoshito Inoko, Zeitschr. f. physiol. Chem. 18. 540 (1893). 



7 W. Jones, ibid. 29. 20 (1900). 



8 A. Kossel, ibid. 22. 188 (1896). 9 A. Ascoli, ibid. 31. 161 (1900). 



10 A. Kossel, Arch. f. (Anat. u.) Physiol. 1891, p. 181. 



11 A. Kossel, ibid. 1893, p. 157. 



12 A. Kossel, Zeitschr.f. physiol. Chem. 4. 290 (1879). 



13 A. Kossel, ibid. 4. 290 (1880). 



14 J. Bang, ibid. 26. 133 (1898). 15 J. Bang, ibid. 31. 411 (1900). 



16 W. Jones and G. H. Whipple, Amer. Journ. of Physiol. 7. 423 (1902) (Holy's 

 Jahresber. 1902, p. 45). 



17 A. Kossel and A. Neumann, Zeitschr. f. physiol. Chem. 22. 74 (1896). 



18 A. Kossel and H. Steudel, ibid. 37. 245 (1903). 



19 A. Kossel and H. Steudel, ibid. 37. 177 (1903). 



