THE NUCLEIC ACIDS 443 



C44H 66 N 20 34 P 4 (pancreas, Bang 1 ). 

 C 41 H 74 N 14 26 P 4 (thymus, Kostytschew 2 ). 

 C 41 H 61 N 16 31 P 4 (wheat-embryo, Osborne and Harris 3 ). 

 C4o H 5 6 N 14 26 P 4 (thymus, Bang*). 



It will be seen that the differences are not inconsiderable, yet a 

 fair agreement is shown in the nucleic acids obtained from the 

 spermatic fluids of fish, the yeast, and the thymus, in respect of the 

 nitrogen- and phosphorus-contents. The guanylic acid differs more 

 widely, a fact which Bang explains by the high amount of guanin 

 which it contains (see p. 459). The inosinic acid which Liebig and 

 Haiser prepared from meat -extract gives rise, according to Haiser, 

 to dissociation-products which differ from those usually obtained, for 

 there are present, besides hypoxanthin and phosphoric acid, a trioxy- 

 valerianic acid, but further investigations into this matter are needed. 



Altmann and Neumann 5 and others describe nucleic acids in 

 their dry state as white, loose, dust-like, and non-hygroscopic powders. 

 They are slightly soluble in cold water (0*3 parts of pancreas-nucleic 

 acid in 100 parts of water) ; in hot water they are much more soluble, 

 and very soluble in alkalies, and also in potassium acetate ; they are 

 precipitated by mineral acids, and dissolved by an excess of acid ; 

 acetic acid precipitates only the pancreas-nucleic acid and not the 

 others. By the addition of an equal bulk of ethyl-alcohol they are 

 precipitated, but most readily by 50 per cent alcohol containing 

 hydrochloric acid, especially if ether be also added, and this method 

 has been employed by Altmann and Neumann for preparing the 

 nucleic acids in a pure state. With most of the salts of the heavy 

 metals nucleic acids give insoluble salts, and are therefore pre- 

 cipitated by copper-, silver-, zinc-, lead-, and iron-salts. Barium-, 

 calcium-, and strontium-salts produce gelatinous precipitates, according 

 to Neumann and Kostytschew. 6 As nucleic acids are also precipi- 

 tated by tannic, picric, and phospho-molybdic acids, they must 

 possess basic radicals like all the other purin derivatives. The colour- 

 reactions of the albumins are, of course, absent. 



The nucleic acids are pluribasic ; Miescher has examined the 

 ammonia and baryta salts of the nucleic acid of the salmon, and 

 Schmiedeberg the copper salt. Other investigators have employed, as 



1 J. Bang, Zeitschr. f. physiol. Chem. 26. 133 (1898) ; 31. 411 (1900). 



2 S. Kostytschew, ibid. 39. 545 (1903). 



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



4 J. Bang, Hofmeister's Beitrdge, 4. 331 (1903). 



5 A. Neumann, Arch. f. (Anat. u.) Physiol. 1899, Suppl. p. 552. 



6 S. Kostytschew, Zeitschr. f. physiol. Chem. 39- 545 (1903). 



