jo Society for Experimental Biology and Medicine. 



In the focal necrosis the average was 28 per cent., in the diffuse 

 necrosis 21 per cent. 



6. No difference could be observed in the rapidity with which 

 the necrotic liver underwent autolysis, the maximum was appar- 

 ently reached in four weeks. This phase of the subject will be 

 discussed in a later paper. 



50 (193) 



The action of nitric acid on the phosphorus of nucleoproteids 

 and paranucleoproteids. 



By A. B. MACALLUM. 



\From the Physiological Laboratory of the University of Tor onto. ~\ 



The manner in which phosphorus is combined in the true 

 nucleoproteids and in those known as the psuedo (para) nucleo- 

 compounds or phospho-proteins has not as yet been definitely 

 ascertained nor has it been determined that the phosphorus in both 

 classes of compounds is similarly or otherwise combined. Burian 1 

 has, it is true, suggested that in true nucleic acids phosphorus is 

 the bond between the No. 7 nitrogen of the purin bases and the 

 remainder of the nucleic acid molecule, but this view is founded 

 on the fact that the nucleic acids do not give the diazo reaction 

 which he regards as characteristic of those purins in which there 

 is no substitution of the imide hydrogen of nitrogen No. 7 of 

 the purin skeleton, an explanation of the reaction that is rejected 

 by Steudel who has pointed out that thymin gives the diazo reaction 

 of Burian although it does not contain nitrogen in the No. 7 

 position. 2 



If Burian's suggestion were accepted it would establish a radical 

 distinction between the manner in which phosphorus is held in 

 nucleic acids and that obtaining in paranucleic acids, for in the 

 latter there are no purin bases. 



Whether we do or do not accept Burian's view, it is possible 

 on other grounds to establish a distinction between the two classes 

 of compounds in regard to the manner in which the phosphorus is 

 combined in them. For this purpose nitric acid may be allowed 



1 Ber. d. d. chem. Ges., vol. 37, p. 708 (1904). 

 * Zeit. fur physio!. Chem., vol. 42, p. 165 (1904). 



