SPECIFICITY OF ANTIVENOMOUS SERA

(SECOND COMMUNICATION.)

IN a previous paper¹ entitled "Specificity of Antivenomous Sera" I drew
attention to the great importance and interest of this question both
from the practical and from the theoretical standpoint. Further, in this com-
munication I brought forward evidence which pointed to an antivenomous serum
being in all probability strictly specific, that is to say, that a serum prepared by
injections of a single pure venom is able to neutralise that venom only and no
other. This evidence, stated briefly, consisted of the following facts:—

       Firstly, the antivenomous serum sent out by Calmette of Lille and prepared
with a mixture of venoms, in which mixture cobra venom greatly preponderates,
while able to neutralise the general action in vivo of cobra venom, has been
shown by Martin and Tidswell to have no effect on the venoms of several of the
Australian snakes. Further, this serum had no antitoxic effect on the poisons
of three of the Indian snakes, namely, Bungarus fasciatus, Vipera Russellii and
Echis carinata.

       Secondly, the serum of a horse prepared by Tidswell with injections of a
pure unmixed venom, namely, the poison of Hoplocephalus curtus, while able
to neutralise the poison with which it was prepared, had no effect on the
venoms of three other Australian snakes, namely, the brown and black snakes
and the death adder. Further, this serum was shown to be quite inoperative
against the venoms of three Indian species, namely, Naja tripudians, Bungarus
fasciatus and Vipera Russellii.

       The observations which led up to these conclusions fell short of a com-
plete study of the question of specificity in several ways.

       In the first place, many of the observations were made with a serum,
namely, Calmette's serum, prepared with a mixture of snake venoms. Although
cobra venom forms the greater part of this mixture, it is à priori evident that
such a serum is not strictly adapted for the settlement of the question of speci-
ficity. This objection also applies to the recent observations published by
Rogers,² as these observations were also made with Calmette's serum.

       In the second place the two sera were tested against the poisons of only
a very few species of snakes.

       In the third place, the sera were tested against only the general actions
in vivo of the several poisons, the experiments being all made on living ani-
mals. No attempt was at that time made to test the sera against any particular
action of the venoms, such as the action which all venoms exert on the red

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