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animals treated with them lived longer than ordinary. To one horse we
gave 10,380 grains of the alkaloids and 373 grains of arsenic in 34 days;
and in this case the toxic effects of the alkaloids were very pronounced,
but we failed to destroy the infusorian. We now deemed it advisable to
drop the cinchona alkaloids, and to pursue the treatment with arsenic
alone. The amount of arsenic which was given in one case was 795
grains in 87 days. The infusorian was absent from the blood for 84
days, and the animal lived for 110 days: here the effect of the drug was
well marked; the infusorian appears to have been destroyed, but before this
happy result was arrived at, the disease had so far advanced that recovery
was not possible. Other cases treated with arsenic were not so successful;
indeed, the above was the most encouraging case we had. Other agents
have been tried: Hydrarg perchlor, both by subcutaneous injection
(2.60 grammes in six days) and by direct injection into the jugular (9 25
grains in one day), but the results were negative: iodine and iodide of
potassium were also given. Iodoform in ether injected subcutancously
(7 grains in two days); injected into the jugular vein, 44 grains, three
days. Potassium bichromate injected into the jugular vein, 23.5 grains
in four days, and by gastric ingestion 2,378 in 16 days. Quinine and
arsenic by gastric ingestion, l,9s0 grains of the former and 72 of the
latter in six days. With regard to quinine, Ranking bad stated that
large doses would bring about recovery. In order to test the veracity of
this statement, we gave in one case six drachms of quinine on one day,
six on the next, and six on the following day; this produced no effect
whatever. Oleum terebinthinæ was also tried. None of the medicinal
agents above mentioned have given us any encouraging results with the
exception of arsenic.

Iodic Hydrarg has also been administered, but with negative results.

Protective Inoculation.—A series of experiments were conducted
to test the efficacy or otherwise of the blood serum as a protective agent
against the inoculated diecase, or, in other words, to ascertain whether
any substance capable of conferring immunity against the disease was
present in it, when obtained from animals in whose circulation the
infusorian of surra had been swarming for some days previously. In
the first series, fresh blood containing numerous infusoria was drawn
from a horse, immediately after death, into sterilised glass vessels, and
set aside for several hours in order to allow of the serum separating.
The serum was then transferred to one of M. Pasteur's filters and forced
through a porcelaiu cylinder. Three rabbits and two gainea-pigs were
then subcutaneously injected with varying quantities during three
days. On the evening of the third day, each animal received sub-
cutaneously 0.2C.C. of blood containing numerous infusoria. Rabbit A,
which had received 3.0C.C. of serum, died in 24 days from surra.