104 Proceedings of Royal Society of Edinburgh. [sess. 
When fed on raw and boiled pancreas, the results were thus : — - 
Allantoin in grammes per 100 grm. pancreas. 
•49 . . Raw 
•24 . . . Raw 
*14 . . . Boiled 
The effect was slighter, but in the same direction as the thymus. 
Salkowski fed a small dog on five successive days upon If kgs. 
boiled pancreas. In the urine 3‘089 grm. allantoin, or 1*074 grm. 
nitrogen, with 40*7 grm. total nitrogen (2*64 per cent, of the 
total). Uric acid and purin bases showed no rise. Seven weeks 
later 2 kgs. pancreas caused only 1-058 grm. allantoin. 
It will thus be seen that in the dog, upon a purin-poor diet, 
about 6 per cent, of the total nitrogen is in the form of allantoin. 
The proportion remains unaltered when liver is administered, and 
when moderate amounts of raw pancreas are given, while it may 
rise temporarily to 14 per cent, when large quantities of raw 
pancreas are eaten. But, even then, the effect of these diets, rich 
in nucleins, was to produce at most a slight change in the proportion 
of allantoin nitrogen to the total nitrogen. 
Conclusions. 
These investigations seem to show : — 
1. That allantoin is a normal constituent of the urine of the 
dog on all diets. 
2. That the administration of raw thymus causes a great increase 
in the production of allantoin (*188 grm. allantoin nitrogen per 
100 grm. thymus gland, or 36'4 per cent, of total nitrogen). 
3. That boiled thymus produces a much less marked effect (*083 
grm. allantoin nitrogen per 100 grm. thymus gland, or 5*3 per cent, 
of total nitrogen), and that therefore the increased formation of 
allantoin, after feeding with raw thymus, is not simply due to the 
nucleins and purins contained. 
4. That liver and pancreas, although rich in nucleins, cause a 
rise of only -08 grm., and *08 grm. respectively of allantoin 
