84
The Imperial Bacteriologist reports as follows:—
Work carried on
at the Laboratory.
"During the last four months the preparation of certain bacterial products, which are of therapettic
value in veterinary practice, has been undertaken.
"Mallein has been made and is now being tested, and it is hoped that several thousand doses will be
available within a short time, and as large a quantity as is found by experience to be necessary will in future
be prepared and kept in stock at the laboratory.
"Tuberculin is also being made, and it is hoped that arrangements may be made for the cattle of dairies
and other places being tested with this material, as the amount of tubercular disease in Indian cattle does not
appear to be very accurately known, although tubercular disease among human beings is only too common in
this country, part of which may possibly be caused through infection from the milk of tuberculous cattle. It
is worthy of note in this connection that it was not until the use of tuberculin on a large scale was introduced
into England and other countries that the extreme prevalence of this disease among cows was discovered,
while it is only by the free use of this re-agent that herds can be freed from the disease and the absolute safety
of the milk in this respect ensured.
"The investigation of Surra has been continued as far as time would permit, and as from recent work of
the Tsetse-fly Committee of the Royal Society, which has just been published, it appears more than ever
probable that this latter disease and Surra are identical, some of the work on Tsetse-fly disease which has
been carried out by that Committee is now being tested in the case of Surra, in order to obtain further evidence
as to the identity or otherwise of the two diseases, for it is evident that, if they can be proved to be one and
the same disease, all the work that has been done on the one affection will be applicable to the other, and the
increased knowledge may possibly lead to important methods of prevention, if not cure.
"As the important rinderpest experiments demanded undivided attention and the almost constant pre-
sence of the Imperial Bacteriologist at the Laboratory, the question of Ludhiana disease could not be taken
up, but it is hoped that the former work may be sufficiently advanced to allow of this being undertaken during
the next cold weather.
"A brief visit was paid to Roorkee and arrangements have been made for material being sent to the labora-
tory for examination in the event of any cases of "Roorkee disease" occurring, while, if the disease become
at all prevalent, the station will be visited in order to allow of investigations being carried on there, Unfor-
tunately, the disease usually runs a course of but a few hours, so that it is impossible to get from the laboratory
to Roorkee after a case has been reported in time to see it, but if in the course of the cold weather work is
being carried on at the Bareilly branch, it may then be possible to do so.
"As it has been reported from South Africa that a fungus has been found which will readily kill off
swarms of locusts, steps have been taken to obtain some of the material for the laboratory, and it is hoped that
it will shortly be received and kept growing here ready to be sent out if required. Although this pest is not
so severe in India as in Africa, yet it at times causes great havoc, and the method appears to be worthy of
rial.
"The preparation of tetanus antitoxine has also been commenced, and two horses having been obtained
for the purpose, the injections have been begun. The process, however, takes several months to carry
through, but the recent discovery of its much more powerful curative value, when it is injected directly into
the brain, over the previous method of its subcutaneous administration greatly enhances the value of the
material, and it is hoped that it will be ready for issue in a few months' time.
"The testing of the spinal cords of dogs which are thought to have died of hydrophobia, and which may
be forwarded to the laboratory for that purpose, is being arranged for."
409. In addition to the above work, certain experiments were carried out to
test the duration of the infection in the skins and bones of animals that have
died of rinderpest. A review of these experiments will be found under the
heading of "Experiments with hides and bones of animals that have died from
Rinderpest," vide page 134.
Summary of experi-
ments on Kinder-
pest carried out
during 1898-99.
410. The Imperial Bacteriologist reviews the various forms of experi-
ments adopted in South Africa with a view of preventing the spread of
rinderpest, and then proceeds to show the conditions existing in India in
relation to the question of protective inoculation. He then gives the follow-
ing summary of experiments on rinderpest as carried out at the laboratory
during the year under review:—
"Pure unfiltered bile.—An animal was Inoculated with 10 c.c. of good green bile, and on the tenth day
was tested with an injection of 10 c.c. of virulent blood. No disease followed. This animal died of colic on the
twenty-fifth day, and on making a post mortem well-marked lesiors of rinderpest were found in the fourth
stomach, and less marked ones in the oæcum. This is very interesting as showing that the animal had
actually suffered from a mild attack of the disease, although he had never presented any definite rise of temper-
ature or symptoms of the disease throughout the time he was under observation, the temperature having be n
taken twice daily. Whether the disease occurred after the injection of bile or after the virulent blood, it is
impossible to say, but such a case may explain the occasional unusually long duration of the immunity after
the bile inoculations.
"A series of animals have been inoculated with bile and will be tested at intervals in order to determine
the duration of the immunity which may be expected to result in Indian cattle as from the use of this method.
Filtered bile. -As so many observers in South Africa have found that virulent rinderpest sometimes
follows injections of bile, it was decided to test the immunising properties of bile that had been passed through
a Pasteur filter and so deprived of all chance of the danger of conveying the infection to the inoculated
animals. Several animals were inoculated with different doses of filtered bile, and subsequently either inocu-
lated with virulent blood or exposed to natural infection in a shed containing animals in an active stage of the
disease. All the animals contracted the disease in various degrees of severity, some dying of it, although in
a smaller proportion than control animals which were inoculated with virulent blood only. It appears then
that only a very slight degree of protection is afforded by this method, and that it is of too uncertain a degree
to allow of cattle, any rate of the hill breeds, being safely passed through a mild attack of the disease by first
inoculating them with filtered bile and subsequently with a small dose of virulent blood. Since these experi.
ments were carried out, a paper has been received in which similar experiments in South Africa were reported to
have yielded identical results, so that it appears to be useless to pursue this question further unless better results
are obtained in plain cattle which have not yet been treated in this way.