350 CHEMISTBT OF THE LEUOOMAINS. 



parent-substance of adenin and guanin, is the best known and prob- 

 ably most important constituent of the nucleus, and as such it has 

 been already credited with a direct relation to the reproductive 

 powers of the cell. This chemical view has already been confirmed 

 by Zacharias, who showed that chromatin of histologists is identical 

 with nuclein. More recently Mathews ' has shown that the chro- 

 matin in herring spermatozoa is a salt-like combination of protamin 

 and nucleinic acid. Liebermann has questioned nuclein as being 

 the source of xanthin compounds, but in this he is not supported by 

 the mass of evidence. In the case of birds, however, it must be 

 conceded that uric acid results by the oxidation of the purin bases 

 and above all by synthesis from urea, amido acids, etc. In mammals 

 uric acid is probably wholly derived by oxidation of the purin bases 

 originating from nuclein. Wiener,* however, has rendered it probable 

 that the synthetic function is also present though to less degree 

 (p. 343). Whether purin bases as well as uric acid may be formed 

 synthetically in birds remains to be demonstrated. 



According to Minkowski (1898) adenin is a powerful poison. 

 When injected subcutaneously it induces increased heart action and 

 rapid death. On feeding it affects the digestive tract and the kid- 

 neys. The constant vomiting induced is probably due to the intense 

 inflammation of the duodenal mucous membrane which may lead to 

 actual destruction of tissue. The effect upon the kidney is seen in 

 the presence in the urine of casts, albumin and of minute sphsero- 

 liths of uric acid. On section the kidney shows changes similar to 

 those observed after injection of urates. The cortex especially 

 reveals the presence of numerous grayish white points which under 

 the microscope are found to consist of bundles of crystals or burs 

 or more often of balls which show a concentric or radial marking. 

 These deposits are undoubtedly uric acid but their origin is un- 

 known. The excessive uric acid may be ascribed to the oxidation 

 of the adenin but this is improbable. It is more likely that adenin 

 favors the accumulation of uric acid by interfering with the de- 

 struction of this product in the liver. The studies of Wiener have 

 shown that the crushed liver of the dog (p. 343) does destroy uric 

 acid. Adenin is not as poisonous to rabbits and man as to dogs 

 (Kruger and Schmid, 1902). 



A continued diet of sweet-breads which as is known are rich in 

 antecedents of adenin produced symptoms of intoxications such as 

 diarrhoea, anorexia, nausea, headache, malaise and abdominal pains 

 (Taylor). The observation of Kossel that adenin is in part excreted 

 unchanged has been confirmed by Minkowski and others. 



Lilienfeld, in his study of the chemistry of the leucocytes, showed 

 that the nuclei of these cells contain a complex body, nucleohiston, 



' Zeits. physiol. Ohem., 23, 399. 



* Archives f. exip. Path. u. Pharm., 42, 898 (1899). 



