x THE NUCLEO-PROTEIDS 457 



called adenylic acid, but it is possible to prepare from the thymus all 

 the four purin and also all the three simple pyrimidin derivatives. 

 Huiskamp l states that the fresh thymus contains about 1 2 per cent of 

 soluble albumin, of which there is contained in 



Nucleo-histone . . . .69 per cent. 

 Nucleo-proteid . . . .19 

 Other albumins . . . .12 



Bang 2 states that the thymus nucleic acid contains two adenin- 

 molecules for each guanin-molecule ; that the nucleic acid contains 

 only two molecules of purin-bases, and that therefore two distinct 

 nucleic acids must exist in the thymus. One of these, the 'normal 

 acid,' contains 1 molecule of adenin + 1 molecule of guanin, and 

 occurs in the true histone-nucleate, while the second acid, built up 

 of 2 molecules of adenin, is the adenylic acid in combination with the 

 parahistone. 



Native nucleinate 



/\ 



I. . I 



histone-nucleinate parahistone-nucleinate 

 (two parts) (one part) 



1 adenin + 1 guanin 1 adenin + 1 adenin 



Kossel 3 obtained from 10 kilogrammes of thymus 120 grammes of 

 nucleic acid. 



The action of dilute mineral acids on the thymo-nucleic acid has 

 been studied by Levene 4 (see under ' Lsevulinic Acid,' on p. 438). 



From the nuclei of pus-cells, i.e. from leucocytes, Miescher 5 pre- 

 pared the first-known nuclein, and Bang 6 isolated nucleo-proteids 

 from a number of lymphatic organs : lymph glands, bone marrow, 

 spleen, white blood-corpuscles, and also from a sarcoma. 



Thymus Nucleic Acid 



Kutscher and Seemann, 7 by oxidising thymus nucleic acid with 

 calcium permanganate, obtained urea and imido-urea, no uric acid 



1 H. Huiskamp, Zeitschr. f. physiol. Chem. 32. 145 (1901). 



2 Ivar Bang, ffofmeister's Beitrage, 5. 317 (1904) ; see also ibid. 4. 115, 331, 362 

 (1904). 



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



4 P. A. Levene, Amer. Jour, of Physiol. 12. 213 (1904). 



5 F. Miescher, Hoppe-Seylers Med. -chem. Untersuchungen, p. 441 (1871). 



6 J. Bang, ffofmeister's Beitrage, 4. 362 (1903). 



7 Kutscher and Seemann, Ber. d. deutsch. chem. Ges. 36. 3023 (1904). 



