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Close observation, which has been maintained since the beginning of the work in August down to the present,
has failed to show any sign of Rinderpest in the animals treated, notwithstanding the fact that the disease has existed
in the neighbouring villages for some time.
I have carried out a series of experiments in order to ascertain if the animals immunised in August and Septem
ber 1897 were still immune in January 1898.
By a reference to my report of 11th October 1897 and appendices, it will be seen that certain animals were
inoculated with bile and later with virulent blood.
On the 28th of January some of these animals were collected at the Experimental Station and tied up amongst
buffaloes Nos. 1 to 8 that had become infected with Rinderpest. These bullocks were fed with the buffaloes, and the
post mortems of the buffaloes, as they died, or were destroyed, were conducted, as it were under their noses. More-
over, virulent material from the sick buffaloes were rubbed on to the bullocks' muzzles and each bullock received
subcutaneously 1 c. cm. of virulent blood from buffalo No. 1 on the 28th January and another 1 c. cm. of a mixture
of virulent blood from buffaloes Nos. II and VII on the 4th February 1898. (Vide Appendix 1).
Subsequently it was decided to enlarge the experiment, and 4 more bullocks were placed in the Experimental
Enclosure, animals that had been inoculated with bile only in the experiments of 5th, 6th, and 7th September 1897
the details are appended (Appendix 1).
The 4 animals were treated in the same way as the other bullocks with this exception, that they received only
one injection of 1 c. cm of a mixture of virulent blood from buffaloes A1 and All on the 12th February 1897. The
details of these experiments are tabulated and appended.
The result of the tests has been that none of the animals showed any outward signs of Rinderpest. The tem.
perature of K/L 4 rose 4/5 of degree F. on the 6th day. The temperature of KV rose from 102 degree to 103-4 degree
on the 6th day.
To resume. 261 head of cattle have been inoculated with the buffaloes' bile, they have shown, up to date,
none of the outward signs of Rinderpest, though the disease existed and has since appeared in the neighbourhood.
Many of them went to work the next day without inconvenience.
Seven animals that had received bile in September were re-tested under conditions far more stringent than any
animals are likely to be submitted to in usual practice. One of these showed a distinct rise in temperature, but none
showed any outward signs of Rinderpest whatever.
Of the 6 animals that had received an injection of bile plus blood in September, two had died of old age and
debility, but none of Rinderpest between the September and January experiments, and four were submitted to the
same stringent test as the other (bile) batch. One showed a slight rise in temperature on the 6th day, which fell on
the 7th day. None of these animals showed any outward signs of Rinderpest whatever.
I have to add that the injection of 1/1000 part of 1 c. cm. of virulent blood is sufficient to cause the usual
visible symptoms of cattle plague to develop.
I have now to report a small series of bile experiments that have been carried out at Belgatchia.
From the 26th June 1897 to 11th September 1897, 21 animals were inoculated with Rinderpest bile, of these
(3 bullock J. A., Bull J. A. I, Bull J. A. 2) were subsequently attacked with natural Rinderpest and one died. These
animals had been injected on the 11th September with 10 c. cm. of bile from a bullock belonging to Beranagore
Municipality that died on the 10th September 1897 of Rinderpest.
These cases are important in regard to the length of immunity conferred by bile.
Bullock J. A. was attacked four months and fifteen days after inoculation and died very quickly.
Bullock J. A. 1 was attacked four months and 24 days after inoculation, his attack was very mild indeed.
Bullock J. A. 11 was attacked five months and five days after inoculation. His attack was mild.
I think it is worth noting that these cases were immunised with bile from a bullock that died of naturally
acquired Rinderpest, whereas the bile used at Kanti came from buffaloes that had been killed. It appears there-
fore:—
(a) That buffaloes' bile, used under the circumstances recorded, confers a longer immunity than the bile of
bullocks that die of the disease.
(b) That in the large majority of cases, the buffaloe bile method which I have used at Kanti confers immunity
for an average of period of five months at least and probably more, but how much longer than five
months the immunity lasts can only be settled by future experiments.
I suggest, however, that my experiments show that this method might be safely used with advantage on Wards,
Estates, &c., when Rinderpest is known to be raging in the neighbourhood, for it would probably confer immunity long
enough for the disease to die out in the surrounding villages. From thence its use might spread as the neighbours
acquire confidence.
I may add that it has been clearly proved that there is no danger of the inoculation with bile conveying Rinder-
pest, if properly performed. It has also been proved that the operation does not interfere with the ordinary work
of the bullocks.
For the present the buffaloe bile method is the simplest way of conferring temporary immunity on cattle in
Bengal. But it has the obvious drawback that a delay occurs in obtaining the bile in necessary quantity and purity.
It cannot be obtained from the cattle for local reasons. A further delay of. about 7 days occurs while the inoculated
cattle are acquiring immunity, because they do not become immune at once. Hence 12 very important days at least,
are lost.
I have made a few experiments with a view to testing the serum method of treating Rinderpest, because it has
been laid down as a principle that immunity extending over a very long period can only be acquired after an attack
and recovery from Rinderpest.
The preliminary difficulty is of course to control the strength of the attack which is to confer immunity, other-
wise the animal may be killed.
Though I am not prepared to offer a definite opinion as to whether a constant control can be maintained over
the virulence or mildness of the disease, it seems probable from what I have done, that by injecting virulent blood
into a healthy animal and immediately afterwards injecting defibrinated blood taken from an immunised case, the
healthy animal becomes subject to an extremely mild attack of Rinderpest and recovers. This is what has happened
in my experiments, but it remains to be seen if the attack is always as mild as has happened up to the present.
Should this method become recommendable for practical use it will have this advantage, viz: that a mild attack
of Rinderpest can be run through a herd (isolated for the purpose) and the owners' mind set at rest for (possibly)
some years.
I do not think this method will commend itself to the ryots of these Provinces, as it is rather too complicated
for them to understand. Moreover, the dose of defibrinated blood required is large, which is also a drawback.
I have been for some time engaged in attempting to prepare a serum of greater immunizing power than is
obtained from animals that have recovered from an ordinary attack of Rinderpest.
Should I succeed, it may be possible to keep a stock of material at Belgatchia, ready for distribution.
Besides the main work reported above, a few other points have come to notice.