THYMUS. 349 



as the other, according to the unanimous opinion of the above-mentioned 

 investigators. According to BANG, whose statements on this point 

 have been substantiated by MALENGREAU, it splits on saturating with NaCl 

 into nucleic acid and histone without yielding any other protein. On 

 this account BANG does not consider this body as nucleohistone in the 

 ordinary sense, i.e., not as a nucleoprotein, but as a histone nucleate. 

 The nucleohistone behaves like an acid, whose salts, especially the cal- 

 cium salt, have been closely studied by HUISKAMP. On the electrolysis 

 of a solution of alkali nucleohistone in water HUISKAMP also found that 

 the nucleohistone collected in traces at the anode, and that the sodium 

 compound is therefore ionized in the solution. The nucleic acid-cal- 

 cium histone-compound has been prepared, it seems, in a pure state by 

 BANG, and he found the following average composition: C 43.69; H 5.60; 

 N 16.87; S 0.47; P 5.23; Ca 1.71 per cent. The question as to what 

 compound contains the A-histone remains to be investigated. 



The nucleohistone prepared by HUISK AMP'S method of precipitating with 

 CaCl 2 is, according to him, a mixture of two nucleohistones, of which one, the 

 -nucleohistone, contains 4.5 per cent phosphorus, and the other, /?-nucleohistone, 

 contains, on the contrary, only in round numbers 3 per cent phosphorus. 1 As 

 the two nucleohistones are poorer in phosphorus than the nucleic acid-histone 

 compound analyzed by BANG, and as HUISKAMP on cleavage of his preparation 

 did not, like BANG and MALENGREAU, obtain pure nucleic acid, it is still a question 

 whether HUISKAMP was working with sufficiently pure substances. 



In regard to the methods used by the above investigators in the 

 isolation of the bodies in question we must refer to the original publications. 



In connection with the so-called nucleohistone, attention must be called to 

 tissue fibrinogen and cell fibrinogen, which are compound proteins, and are claimed 

 by certain investigators to stand in close relation to the coagulation of the blood. 

 These may be in part nucleoproteins and in part also nucleohistones. To this 

 same group belong also the important cell constituents described by ALEX. 

 SCHMIDT 2 and called cytoglobin and preglobulin. The cytoglobin, which is 

 soluble in water, may^ be considered as the alkali compound of preglobulin. The 

 residue of the cells left after complete extraction with alcohol, water, and salt 

 solution has been called cytin by ALEX. SCHMIDT. 



Besides the above-mentioned and the ordinary bodies belonging to 

 the connective-tissue group, small quantities of fat, leucine, succinic 

 add, lactic acid, sugar, and traces of iodothyrin are present. According 

 to GAUTIER 3 arsenic also occurs in very small amounts, and no doubt here 

 as well as in other organs it is related to the nuclein substances. The 

 richness in nuclein bodies explains the occurrence of large quantities 

 of purine bases, chiefly adenine, whose quantity, according to KOSSEL 

 and ScHiNDLER, 4 is 1.79 p. m. in the fresh organ and 19.19 p. m. in the 



1 Zeitschr. f . physiol. Chem., 39. 3 Compt. rend., 129. 



2 See foot-note 1, p. 295. 4 Zeitschr. f . physiol. Chem., 13. 



