THB PHYSIOLOGY OF POISONING 205 
substances (casein, albumins of ox-serum) in solution, has shown 
that Cobra-venom and that of Vipera disintegrate the albuminoid 
molecule; but the latter remains soluble after the addition of 
formol and is no longer precipitable by acetic acid. The hydro- 
lysis never leads to the stage of peptone, but only to the forma- 
tion of albumoses which give biuret-reaction. i 
The action of venoms upon fibrin may be demonstrated in vitro 
by bringing sufficient quantities of venom, 1 centigramme, for 
example, into contact with small fragments of non-heated fibrin, 
derived from blood clots from an ox, rabbit, or birds, and carefully 
washed. These fragments soon separate from each other, and 
become dissolved in a space of time which varies according to the 
venom used. The VIPERINE-venoms, especially those of Lachesis 
and Ancistrodon, are the most active. Viper-venom is much less 
so, and the venoms of CoLUBRID# are the slowest. 
This proteolytic action of the various venoms corresponds pretty 
exactly to their coagulant and decoagulant action on rabbit- or 
horse-plasma, so that, as I have already stated, we must suppose 
that the property possessed by VIPERINE-venoms of more or less 
rapidly dissolving blood which they have caused to coagulate, 
results from the fact that these venoms contain, in addition to a 
coagulant substance, another substance which is strongly proteolytic. 
The latter is destroyed by heating. Lachesis-venom, when 
heated to 70°C., no longer has any dissolving action on either 
gelatine or fibrin. Moreover, antivenomous serum furnished by 
horses vaccinated against heated venoms does not prevent proteo- 
lysis by non-heated venoms. On the other hand, the serum of 
animals vaccinated against VIPERINE-venoms, simply filtered by 
the Chamberland process and non-heated, affords perfect protec- 
tion to gelatine and fibrin against the dissclving action of these 
venoms. 
