PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 187 
fibrinogen,” and venom may be introduced in great quantity, 
without increasing the coagulability of the blood, once the initial 
positive phase is passed, and a negative phase established, if the 
solution be allowed to flow very slowly into a vein. 
In 1888 Wooldridge published a remarkable result he had 
obtained with the injection of his “ fibrinogens” viz.—that the 
injection of one dose conferred upon the animal immunity from 
further injections. Exactly the same occurs with the venom. 
The first injection produces an immunity, as far as the clotting 
of the blood in the vessels is concerned, from the effects of 
future doses, even when those are very large. 
I have had many opportunities of confirming this statement of 
Wooldridge. An analogous result has been obtained with the 
intravenous injection of albumoses, although the effect of these 
upon the blood is of the reverse order. Schmidt Mulheim? found 
that when the coagulability of the blood had reappeared after it 
had for the time being vanished owing to a first large injection of 
albumoses, it was not influenced by a second injection. The 
first injection must however be a full one or the immunity is not 
complete. 
The parallelism, as far as the coagulation of the blood is con- 
cerned between the results of the injection of “ tissue-fibrinogen” 
and of venom, is, as has been pointed out, maintained when one 
examines the conditions under which the two kinds of fluid blood 
may be induced to clot. 
Both these kinds of blood remain fluid, or clot only after the 
lapse of some hours, the time intervening before the onset of 
coagulation depending in both cases on the amount of the agent 
injected ; and by injections of nucleo-albumens and of venom, one 
ean obtain a series of plasmas which, as regards the circumstances 
under which they may be made to yield fibrin, exactly correspond. 
ee eee 
1«g. * * ’ . 
1888 Schutzimpfung auf Chemischen Wege.”—Du Bois Reymond’s Arch. 
2 ‘ A 
Du Bois Reymond’s Arch., 1880, Se 52. 
