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Are Venomous Snakes auto-toxic?

AN INQUIRY INTO THE EFFECT OF SERPENT-VENOM UPON THE SERPENTS THEMSELVES.

BY

SURGEON L. A. WADDELL, M.B.,

DEPUTY SANITARY COMMISSIONER, BENGAL.

INTRODUCTORY.

Practical bearing of inquiry.

    An interesting question which presents itself in studying the phenomena of
serpent-poisoning is that which refers to the insus-
ceptibility or otherwise of a serpent to its own
venom, or that of its fellows. And this question is not without a practical
bearing upon the treatment of snake-bite: for, were such immunity proved to
exist, a study of its conditions might possibly afford indications for combating
the action of the venom on man.

Seeming anomaly of subject.

    That an animal should be subject to poisoning by one of its own normal
secretions, must, primâ facie, seem improbable, as this
would prove detrimental to the individual and to the
species. And especially so, when, as in the present case, the exposure to poison-
ing would be habitual: for snakes are frequently receiving accidental injuries to
the mouth, with abrasion of the mucous membrane of the buccal cavity, and
thus, not unfrequently, must absorb some of their own venom.1

    Should, on the contrary, snakes be proof against poisoning by their own
venom, then the problem presents itself of how to account for the organism of
the serpent being able to resist a chemical poison which is so deadly to most
other animals.

Conflict of opinion on question.

    As to whether such insusceptibility really exists, authorities differ widely in
opinion.

    On the one hand are those who assert the existence of this insuscep-
tibility:—

Favouring view of insuscepti-
bility.

    Fontana, in 1765, experimenting on the European Viper (Viper aspis? ) con-
cluded that "the venom of the viper is neither a
poison to the viper itself, nor to those of its own
species."2

    1This fact was pointed out long ago by FONTANA in regard to the Viper ('Treatise on the Venom of
the Viper, &c., ' Skinner's transl. London, 1795, Vol. I, p. 274).

    2loc. cit. p. 34. His experiments on this head, over twenty in number, were admirably conceived and
carried out.