PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 185 
nounced, with the reactions which have been found to characterise 
the blood drawn during the corresponding phase following the 
intravenous injection of “ tissue-fibrinogen.” 
Wooldridge in one of his papers' thus summarises the results 
obtained by injecting tissue-fibrinogen :—“ If a solution of tissue- 
fibrinogen be injected into a dog in varying quantity, the effects 
observed are: with very small quantities no discoverable intra- 
vascular clotting occurs, but the blood drawn off after the injection 
clots very slowly, 1 — 2 hours intervening ; with larger quantities 
intravascular clotting takes place, being, as a general rule, chiefly 
confined to the portal venous system—the extent of clot being 
greater as more tissue-fibrinogen is injected. The shed blood 
(from other areas) will not clot. The more tissue-fibrinogen there 
. has been injected, the more complete is this prevention of the 
(extravascular) clotting —the interval between the drawing off 
and the clotting varying from two to thirty hours. In most 
eases the blood can be readily made to clot firmly by additions, 
such for instance, as the ordinary fibrin-ferment, and in the great 
majority of cases it clots firmly on standing.” 
A few pages further on in the same paper, he says :—‘ Further, 
the injection of a very large quantity of tissue-fibrinogen always 
leads to the production of a shed blood entirely noncoagulable, 
either spontaneously, or on addition of leucocytes or tissue- 
fibrinogen. The only difficulty is this, that frequently the circu- 
lation is arrested before the required quantity is got in, and then 
only marked slowing of the shed blood is produced.” 
A summary of my experiments, showing the effect on the 
‘Seagulability of the blood from the intravenous injection of 
different amounts of venom, could well enough be given in the 
ape words as those used by Wooldridge, substituting only, 
venom” for “ tissue-fibrinogen.” 
2 Wooldridge also found that variations in the condition of an 
_ animal were followed by alterations in the amount and distribution 
1 “ Nature of Coagulation,” p. 31. 
