192 VENOMS 
Antivenomous anticolubrine serum, that is to say, that fur- 
nished by horses vaccinated against the venoms of the Cobra and 
the Krait, does not prevent coagulation by coagulant venoms. 
This need not surprise us, since the coagulant substances in venoms 
are destroyed by heating, and the animals vaccinated in order to 
obtain antitoxic serum are usually inoculated exclusively with 
heated venoms. 
It is easy, however, to obtain active serums specific against 
the coagulant venoms; it is sufficient to treat these animals by 
inoculation with progressively increasing doses of the same venoms 
unheated. I have had no difficulty in achieving this result with 
small laboratory animals (guinea-pigs and rabbits) and also with 
the horse, but I have never had at my disposal a sufficient amount 
of the venoms of Lachesis or Vipera russellii to undertake with 
them the regular acquisition of large quantities of horse-serum, 
at once antineurotoric and anticoagulant. The preparation of such 
a serum, nevertheless, presents much interest for certain countries, 
such as Burma, where the Daboia (Vipera russellii) is almost as 
common as the Cobra, and Brazil, where nearly all the casualties 
due to venomous snakes are produced by Lachesis.! 
II.—ANTICOAGULANT VENOMS. 
Contrary to what is observed with the venoms of VIPERID® in 
general, all the venoms of COLUBRIDÆ and, as exceptions to the 
rule, the venoms of some North American CROTALINÆ (Ancistrodon 
contortrir and A. piscivorus) suppress the coagulability of the 
blood in vivo and in vitro. It is, however, important to observe 
that, 2x vivo, the blood remains fluid after death only if the dose of 
venom absorbed has been sufficient. Jn vitro this phenomenon is 
easier to study, and has been the subject of several important 
memoirs. 
' At the Serum-therapic Laboratory of Sao Paulo (Brazil), Dr. Vital, Brazil, 
is at the present time preparing serum specific against Lachesis-venom, 
