191 1] Walter H. Eddy 8i 



the predominance of basicity in histones, neutrality in albumins, 

 and acidity in nucleoproteins and mucoids. Robertson has pointed 

 out how the presence of these two types of radicals in the molecule 

 explains the tendency to polymerisation and the production of " in- 

 ternal salts." If we represent the Compound as 



\C00H 



it is easy to see that these radicals may unite with acid and basic 

 groups to form addition Compounds. On the other band the NH2 

 radical unites, in many cases, with the COOH group within the 

 Compound. The extent to which this can take place gives us new 

 views of the possible complexity of a protein molecule. Ostwald 

 has gone so far as to suggest that a protein Solution has a structure, 

 is in fact a single giant molecule and that all its parts are chemically 

 combined chains. 



The study of the various nucleoproteins by Kossei, Osborne, 

 Levene, and others, has also thrown light upon the way in which 

 protein molecules may be constructed. The following scheme shows 

 the main cleavage lines for nucleoproteins : 



Nucleoprotein 

 ! 



Simple protein Nuclein 



I . . 1. 



Simple protein nucleic acid 



(Histone, 

 Protamin, etc.) 



PO4 Pyrimidin bases (cytosin, Purins (adenin, Carbo- 



uracil, thymin) guanin) hydrate 



Much work has been done to establish the identity of the nucleic 

 acids of plant and animal cells with one another and the present 

 conclusions all point to such an identity. Work has also been done 

 to establish the nature and intramolecular connections of the car- 

 bohydrate radicals. In a recent paper Levene has suggested that in 

 the nucleic acid of the liver and pancreas we have a pentose which 

 he calls fZ-ribose, and that this nucleus is bound to the PO4 by its 

 OH group and to the purins by its aldehyde group. It is generally 

 agreed that the carbohydrate portion of a nucleoprotein is pentose- 

 yielding though it may, in a few cases, yield hexose. 



