THE. PHYSIOLOGY OF POISONING 189 
explained these differences by the hypothesis that, in cases of 
rapid death, the blood had not had time to become modified by 
the venom. 
Later on it was found by Sir Joseph Fayrer, and subsequently 
by Halford,’ in Melbourne, C. J. Martin, in Sydney, G. Lamb,’ 
in Bombay, and recently by Noc, in my laboratory, that the 
venoms of CoLUBRIDÆ, especially those of Naja tripudians and 
AUSTRALIAN species of this family, always leave the blood fluid 
after death, while the venoms of VIPERID®, on the contrary, are 
usually coagulant. 
On the other hand, it was observed by Phisalix,’ and at an 
earlier date by Mosso, of Turin, that the venom of Vipera berus 
causes the blood of the dog to lose its coagulability, while, on the 
contrary, the same venom is actively coagulant as regards the 
blood of the rabbit. 
How are these differences of action to be explained? It was 
found by Delezenne,?> who made an excellent study of the 
phenomena following the injection of peptone, extracts of organs, 
and other anti-coagulant substances into the organism, that those 
of these substances that render the blood non-coagulable always 
dissolve the leucocytes, and thus set at liberty two antagonistic 
bodies which they contain. One of these substances is coagulant 
and is found retained by the liver, while the other remains in 
solution in the plasma, and keeps the blood fluid after issuing 
from the vessels. 
Now, certain extracts of organs, ricin, abrin and certain venoms 
in weak doses, retard coagulation, while in large doses, on the 
contrary, they produce partial or general intravascular clotting. 
It is believed by Delezenne that the explanation of this 
1 Medical Times and Gazette, vol. ii., 1873. 
2 “On the Physiological Action of the Venom of the Australian Black Snake,” 
Proceedings of the Royal Society of New South Wales, July, 1895. 
3 Indian Medical Gazette, December, 1901. 
4 Comptes rendus de la Société de Biologie, November 4, 1899. 
> Ibid., October 28, 1£99, 
