Medical Officers of the Army of India.

43

     The following experiment illustrates the phenomena attending the direct
introduction of minimal lethal doses, of Daboia-venom on the one hand and of
cobra-venom on the other, into the circulation.

     Experiment LXIII. —(a ) A sample of Daboia-venom was carefully tested
and the minimal lethal dose requisite to occasion general convulsions and death
ascertained to amount to between 0.005 and 0.004 gramme.

     11-7 A.M. A fowl received an intrajugular injection of 0.005 gramme in
0.5 c.c. of distilled water.

     Furious general convulsions set in before the bird could be put down and
death occurred immediately afterwards. The blood was of a dull brick-red
colour. It brightened in some degree on exposure to air, but was absolutely in-
coagulable.

     (b ) 10-50 A.M. A fowl received an intrajugular injection of 0.0005 gramme
of dried cobra-venom, of which that amount constituted a minimal lethal dose.

     No appreciable symptoms whatever manifested themselves until between
2 and 3 P.M., but they then began to appear, ran their normal course and
terminated in death between 7 and 8 P.M.

     The phenomena which attend the mixture of various amounts of Daboia-
venom with blood outside the body are also, as the following experimental data
clearly show, quite district from those which attending the action of cobra-
venom.

     Experiment LXIV. —A covered glass capsule having been carefully steri-
lised, a solution of 0.003 gramme of dried Daboia-venom of ascertainedly
highly lethal property, in 1 c. c. of sterilised distilled water, was introduced into
it, and 19.69 grammes of blood added directly from the throat of a fowl at
11 A.M.

     The blood at once became of a vivid scarlet colour and rapidly underwent
coagulation, but the clot was persistently of an extremely soft, tremulous
consistence.

     11-30 A.M. The blood consisted of a relatively small clot, vivid scarlet superficially
and darker red in substance, floating free in a large bulk of brilliant
scarlet opaque serum.

     12 Noon. The serum had now deposited a scarlet sediment of blood corpuscles
and was of a muddy colour.

     2 P.M. The clot was relatively very small, widely separated from the sides of
the vessel and floating free in the muddy serum. The deposit had
now lost its scarlet colour but portions of it, when exposed to the air,
rapidly re-gained it. There was no appreciable evidence of any
solution of corpuscles.

     On the following day the clot was small and of a very dark plum colour,
and 11 c.c. of very dark, opaque plum-coloured serum surrounded it. Both

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