THYMONUCLEIC ACIDS. 177 



nucleic acid, from the thymus gland. The a -acid is soluble with difficulty, 

 and in proper concentration gives a sodium salt which gelatinizes, 

 and a barium salt which is precipitated by barium acetate in substance 

 (KosTYTSCHEw). The barium salt of the /?-acid is not precipitated by 

 barium acetate. The a-acid is designated as anhydric by SCHMIEDEBERG x , 

 and the /?-acid as hydrate, and the first can be transformed into the second 

 by heating. This transformation, according to KOSTYTSCHEW, is a decom- 

 position whereby two-thirds of the purine bases are split off. 



According to SCHMIEDEBERG the thymus nucleic acid is identical 

 "with the salmo-nucleic acid (from salmon sperm), and also according 

 to STEUDEL probably with the acid from the herring sperm. Other 

 nucleic acids, at least very closely related to this nucleic acid, have been 

 prepared from the sperm of the burbot (Lota vulgaris) by ALSBERG, 

 of the sturgeon (NOLL) and of the sea-urchin (MATHEWS), also from ox- 

 sperm, brain, spleen (LEVENE), pancreas (LEVENE, v. FURTH and JERUSA- 

 LEM, STEUDEL), mammary glands and kidneys (LEVENE and MANDEL 2 ) 

 and from other organs. 



We are at the present time not agreed as to the formula for the most 

 carefully studied thymonucleic acids (from the thymus, herring and sal- 

 m< n sperm). According to the numerous analyses of SCHMIEDEBERG and 

 his collaborators for every 4 atoms of phosphorus there occur 14 atoms 

 of nitrogen. The relationship of C to P was 40 to 4 and the relation 

 C to N in 12 out of 15 preparations was 40 to 14, and only in 3 prepara- 

 tions 40 to 15. From these facts SCHMIEDEBERG has given the acid 

 the formula C4oH5 6 N 14 Oi6.2P 2 O5. According to STEUDEL for every 4 

 atoms of phosphorus we have 15 atoms nitrogen and from this he has 

 calculated the formula C43H 5 7Ni5Oi2.2P2O5 for the thymonucleic acids. 

 The results obtained on elementary analysis are not sufficient to decide 

 between these two formula?. 



On the decomposition of the nucleic acids the purine bases are first 

 more or less completely split off and correspondingly also various inter- 

 mediary products are obtained. One of these is the heminucleic acid 

 obtained by ALSBERG and containing only one-half of the purine bases, 

 and another body is thymic acid, which is obtained on heating the free 

 acid with water, when guanine, adenine and cytosine are simultaneously 

 split off. Thymic acid forms a barium salt soluble in water, having the 

 formula Ci 6 H23N 3 P2Oi2.Ba (KOSSEL and NEUMANN 3 ). 



1 Neumann, Arch. f. (Anat. u.) Physiol., 1898 and 1899 Suppl.; Kostytschew, 

 Zeitschr. f. physiol. Chem., 39; Schmiedeberg, 1. c. 



2 Alsberg, Arch. f. exp. Path. u. Pharm., 51; Noll, Zeitschr. f. phyisol. Chem., 25; 

 Mathews, ibid., 23; v. Fiirth and Jerusalem, Hofmeister's Beitrage, 10 and 11; Steudel, 

 Zeitschr. f . physiol. Chem., 53. See also foot-note 3, p. 176. 



3 Alsberg, 1. c.; Kossel and Neumann, Zeitschr. f. physiol. Chein., 22. 



