188 C. J. MARTIN. 
So close is the parallelism between the two series of phenomena, 
that one is inevitably driven to enquire whether after all there 
may not underlie both an actual identity of process. But 
in thus enquiring, one is confronted by the very striking fact that — 
in the venom experiments, only an exceedingly small quantity of ; 
the active agent is required to produce an effect negative or 
positive on the coagulability of the blood. ; 
Wooldridge stated that it required 1-5 to 2 grammes of his 
“ tissue-fibrinogen ” to produce intravascular clotting, ina medium — 
sized dog. ‘This I imagine, from my own experiments with 
“ tissue-fibrinogen,” is a rather high estimate. However this may 
be, it is certain that in the one case we are dealing with the — 
injection of grammes, and in the other with thousandths, or ten 
thousandths of a gramme. He also found that his “ fibrinogen” 
disappeared in the process of coagulation and presumably took — 
part in the formation of the clot.' : 
On account of the minute quantity of venom required to pre 
duce the intravascular clotting, it is hard to conceive that it cal 
operate by any such direct action. An important differen 2 
‘between the two series of phenomena which I have always noticed 
is, that whereas with injections of “tissue-fibrinogen” the clotting ; 
occurs practically instantaneously, so much 80, that it frequen®y 
causes blocking in the vein before one has had opportunity “ 
finish the injection, with venom injections there is an interval of 
at least 90-100 seconds before clotting occurs in the a 
but notwithstanding this delay in onset, the clotting in ast : 
venom injections is much firmer and more extensive than I ha 
ever been able to obtain with “ tissue-fibrinogen.” 
Pekelharing,? Wright,® and Halliburton,* have recently sho¥™ 
that the bodies Wooldridge designated <tisgue-fibrinogeD 
largely of nucleo-albumens, and that these nucleo-albumens 
the active agents in producing intravascular clotting- 
a 
yp 
_ 1“ Nature of Coagulation,” and “ Ueber intravasc. Gerinnung: 
2 “ Virchow’s Festschrift,” Bd. 1. 
3 “ Proc. Roy. Irish Acad.” 3rd Series, Vol. I1., No. 2. 
4 “ Jour. of Physiol.” Vol. x111., Supplementary Number. 
