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The Committee facilitated the application of such treatment as far as possible, and
the Medical Officers of plague hospitals were ordered to take special notes of the same,
so that all cases were studied and watched with the keenest interest.
In order to understand the subject, it must be borne in mind that the effects of
plague and its symptoms are due to chemical toxines produced by a living diplo-
bacillus acting on the fluids and tissues of a living animal body.
The principle of that form of treatment of plague with which M, Haffkine's
name is associated, viz., the prophylactic or anti-microbic treatment is one of prevention
or modification of the disease by injecting into the body graduated doses of the
plague chemical products.
M. Haffkine had already applied this method to the preventive treatment of other
diseases, such as cholera and typhoid fever, and he has been working in Bombay with
indefatigable enthusiasm, since very early in the course of the epidemic, to produce a
similar method of preventive treatment for plague.
The basis of the process is to make cultures of the plague bacillus of a certain
strength in artificial fluids possessing high nourishing properties with regard to these
microbes, and after the bacilli have had a defined period of activity in the fluid, they
are killed by the application of a standard degree of heat, disintegrating as little as
practicable their chemical products. This mixture of soluble toxines and suspended
dead bacilli is then injected under the skin in very carefully-measured quantities, and
mild re-actionary symptoms of plague are thereby produced.
By repeating the subcutaneous injections (or inoculations as they are popularly
termed) the system is modified by the artificial toxines, and its tissues are thereby
rendered immune and resistant to the poison of living plague microbes. The
difference between the symptoms of the prophylactic treatment of plague and those
of true plague is both one of degree and of kind. In the former the toxines are very
moderate in amount and calculated on most careful and thorough scientific principles,
according to the degree of resistance of the body to their reaction, which is also
arrived at by an intricate series of experiments ; moreover, no living virus is intro-
duced into the system. In plague the tissues and fluids of the host are invaded by
the living active bacilli and have no resisting effect against the reproduction of the
micro-organism which proceeds with great rapidity and with such overwhelming
intensity that the poisonous effects are irresistible and fatal to those attacked in the
proportion of from 50 to 100 per cent. according to the virulence of the microbe and
the susceptibility of the host, both of which are liable to variation. M. Haffkine
has applied- his treatment to many thousand people, but in the 2,538 patients that
have come under the observation of the Committee in the plague hospitals only
three cases were admitted in which this treatment had been but partially tried (i.e.
they had not had the full number of saturation doses given them), and they all
recovered. M. Haffkine's report will no doubt deal extensively with this subject.
The anti-toxin serum treatment with which Dr. Yersin's name has been so pro-
minently associated is based on an entirely different scientific principle to that of the
prophylactic treatment. It is a direct form of treatment, and its aim is to cure or
alleviate the disease when the individual has been attacked by the living virus and
already shows symptoms of plague. It rests on sound and well-proved laws of bacteri-
ological science, which show that the ravages of a disease of the same nature as plague
can be controlled, by adding to the fluids of a body which has been invaded by the
bacillus a material which has a resisting power to the development of the disease.