SOME OBSERVATIONS ON THE POISON OF RUSSELL'S VIPER.
(Daboia Russellii.)

       MUCH light has of late years been thrown on the physiological action of
the venoms of most of the poisonous snakes. Thus Weir Mitchell ¹ in
America, has carefully investigated the nature and action of the venom of the
American rattle-snake (Crotalus); Martin ²of Melbourne has made similar
researches on the poisons of the Australian black snake (Pseudechis) and tiger-
snake (Hoplocephalus curtus); and Wall³ and Cunningham ⁴, in India, have pub-
lished observations on the physiological actions of the venoms of the cobra (Naja
tripudians) and of Russell's viper (Daboia Russellii). In addition to this,
Kanthack ⁵ , Stephens ⁶and Myers⁷ have done valuable work, principally on the
hæmolytic action "in vitro" of those venoms. Finally, Calmette and Fraser⁹
have investigated the question of artificial immunity against those poisons, and
both have been able to obtain a serum which has a specific action, at least
against the venom of the cobra.

       While all the older observers, such as Brunton and Fayrer ¹⁰, seem to have
regarded the physiological action of cobra venom as essentially identical with
that of the poison of vipers, such as Daboia, the result of the investigations
mentioned above has been to show beyond a doubt that this is not the case,
and that cobra poison exercises its poisonous effect in quite a different manner
from the venom of true vipers. However, in a recent publication¹¹ issued from
Lille it is stated that Calmette has shown that snake venoms differ from one
another only in the degree of their toxicity, and that they are all of the same
nature. It is stated, further, that an animal immunised with the most toxic
venom, i.e., cobra poison, furnishes a serum which is protective against, and
anti-toxic to, the venom of all species of snakes. We shall return to the con-
sideration of these statements later.

       It would appear from a perusal of the literature of the subject that, while
the descriptions of the symptoms which the different venoms produce in man,
and when artificially inoculated into animals, coincide fairly well, there is a great
divergence of opinion amongst different observers regarding the physiological
cause of these symptoms. Thus, while almost all writers, who have specially

A