CHEMICAL EXAMINATION OF THE BLOOD. 323 



Properties. Thus obtained, nucleohiston represents a snowy-white, 

 fine powder, which is insoluble in benzol, alcohol, chloroform, methyl 

 alcohol, ether, and acetic acid, but is soluble in water, glacial acetic 

 acid, concentrated nitric acid, and hydrochloric acid, in solutions of 

 sodium carbonate, sodium hydrate, ammonia, and, when freshly pre- 

 cipitated, also in solutions of sodium chloride and magnesium sul- 

 phate, especially in the presence of a little acetic acid. On boiling 

 with water, or on treating with baryta water or dilute hydrochloric 

 acid, nucleohiston is decomposed into a nuclear nuclein, the so-called 

 leuconuclein^ and an albumose-like substance, histon, which Kossel 

 first obtained from the nuclei of the red corpuscles of the goose. It 

 may therefore be regarded as a nucleo-albumin, but differs from most 

 of the other representatives of this group in the large amount of 

 phosphorus 3.025 per cent. which it contains. The histon radicle 

 possesses marked basic properties, and readily combines with acids. 

 From its acid solutions it is precipitated by ammonia, and it is 

 insoluble in an excess of the reagent. The leuconuclein, on the 

 other hand, has markedly acid properties. On treating with an 

 alcoholic alkali solution, it is decomposed into an albuminous sub- 

 stance and a nucleinic acid, which is termed thymonucleinic acid. 

 On further decomposition this yields an acid phosphoric radicle, 

 and nucleinic bases, among which adenin and guanin prevail. On 

 boiling with water the acid radicle is transformed into so-called 

 ihyminic acid, which on treating with strong sulphuric acid gives 

 rise to thymin. If, on the other hand, the nucleinic acid is 

 treated with dilute boiling mineral acids, or with superheated steam, 

 adenin, thymin, and another basic substance, cytosin, are obtained, 

 as also ammonia, formic acid, phosphoric acid, and Isevulinic acid ; 

 the presence of the latter suggests that in the nucleinic acid radicle 

 a carbohydrate group also exists. 



The nucleohiston, as such, may be regarded as an acid salt, as 

 it is capable of binding a certain amount of calcium and sodium. 

 Its elementary analysis has given the following results : carbon, 48.46 ; 

 hydrogen, 7; nitrogen, 16.86; phosphorus, 3.025; sulphur, 0.701; 

 and oxygen, 23.95 per cent. 



The chemical analysis which Lilienfeld made of the leucocytes 

 of the thymus gland, and which probably expresses the constitution 

 of all leucocytes, gave the following results : 



Water 88.51 percent. 



Solids . 11.49 



Albumins 1.76 



Leuconuclein 68.78 



Histon 8.67 



Lecithin 7.51 



Fats 4.02 



Cholesterin 4.40 



Glycogen 0.80 



Nuclein-bases as silver salts 15.17 



Total phosphorus 3.01 



Total nitrogen 15.03 



