96 Proceedings of Royal Society of Edinburgh. [sess. 
Not only is allantoin known to be normally present, but when 
disturbances in the metabolism are produced by drugs its amount 
may be increased. 
Pohl (5) failed to find allantoin in the tissues of the normal dog, 
but in hydrazine poisoning he found it in the liver and in traces else- 
where. On a few hours’ autolysis of the organs, allantoin appeared 
chiefly in the intestinal mucous membrane and in the liver. 
Hydroxylamine may cause the appearance of allantoin, but it 
does not appear with arsenic or phosphorus (Pohl) (5). 
In dogs diamido sulphate injected in doses of *05 grm. per kilo 
causes coma and death, with the presence of allantoin in the urine 
(Borissow) (6). Hydrazine sulphate does not cause the production 
of allantoin. 
In the urine of some animals, e.g. the dog, allantoin largely takes 
the place of uric acid, and the administration of uric acid has been 
said to lead to the excretion of allantoin, the uric acid being 
supposed to be oxidised and hydrated with the splitting off of 
C0 2 — 
C 5 H 4 N 4 0 3 + 0 + H 2 0 = C 4 H 6 N 4 0 3 + C0 2 . 
Thus Salkowski (7) demonstrated its presence after feeding uric 
ucid to dogs. When 4 grammes were given on each of two suc- 
cessive days, 1-42 grammes of allantoin were recovered. Mendel 
and Brown (9) obtained a considerable yield of allantoin after feeding 
uric acid to cats. Poduschka (8), on the other hand, found that the 
administration of two grammes of urate of soda caused no increase 
in the allantoin of a dog’s urine. Swain (11) has failed to find 
a marked transformation of uric acid to allantoin. After the 
administration of 9 grammes of uric acid, only 1 gramme of 
allantoin appeared in the urine. 
Minkowski (10) showed that when liypoxanthin is given, 77 per 
cent, appears as allantoin, and that 9 methy-adenin also causes an 
increase of allantoin. He expresses the view that in the dog the 
metabolism of the purins still in nucleic acid more readily yields 
allantoin than the metabolism of the free purins. According to 
his observation adenin, the purin of the thymus, is not changed to 
allantoin, and Stadthagen (12) found that guanin, the purin of the 
pancreas, was not changed. 
