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Scientific Memoirs by

the lethal value of the sample of venom in use being such that 0.006 gramme in
0.5 C. C. of water caused violent general convulsions and death in fowls of 1
kilo. in weight within ten minutes. Slight local muscular action ensued, and
during the rest of that day and the whole of the following one, conspicuous
lameness was present. The animal became very dull, refused all food, and
remained almost constantly lying down for four days. On the fifth day after
the injection it appeared to be livelier, and once more began to feed. Nine days
after the first injection, and when complete recovery appeared to have occurred,
a second dose of 0.01 gramme of dried venom was administered. Conspicuous
dulness was present during the whole of that day and the following one, but
on the latter the animal began to feed again. A week later it received a third
injection of 0.015 gramme, and after this at intervals of four or five days' dura-
tion, a series of steadily increasing doses was administered, until six weeks after
the beginning of the experiment the dose amounted to 0.055 gramme. The
animal did not bear the treatment nearly so well as the fowl of the previous
experiment did, for a certain amount of dulness and loss of appetite continued
to manifest themselves after each injection, and a continuous and progressive
loss in condition occurred, which had become so marked at the time at which
the injection last alluded to was administered that it appeared to be undesir-
able to push the treatment further for the time being. An interval of nearly
three months' duration was accordingly allowed to elapse, and an injection of
0.05 gramme, or an amount only a little less than that which had been last
employed, was administered. Conspicuous local irritation ensued, as evinced
by a large amount of swelling around the site of the injection, and the usual
dulness was present for some time, but the animal began to feed again after the
lapse of a few hours.

       The principal value of this experiment is to demonstrate that, in the case
of habitual treatment with viperine venom, just as in the case of similar treat-
ment with colubrine venom, the resultant immunity is not a mere temporary
one, like that arising under the influence of the introduction of extraneous anti-
venene, but persists over very considerable periods and must, therefore, be owing
to correspondingly persistent reactive manufacture of antivenene by the system.

E.—Experiments dealing with the natural immunity of the Common
      Mungoose (Herpestes Mungo ) to the action of Snake-
      venoms.

       Experiment I. —A mungoose, weighing 1,160 grammes, received an injec-
tion of 0.0075 gramme of dried cobra-venom, i.e., a minimal lethal dose for fowls
of about one kilo. in weight.