85
"Glycerinated bile.—This method has also been tested, but so far without success. Five animals were
inoculated with the same dose as is recommended by Dr. Edington for the large South African cattle, which
is more than three times that which would be required in these small hill animals, if their weight is taken into
account. Two of these animals unfortunately developed a naturally acquired disease in less than ten days and
another on the tenth day, and all died. Two others were inoculated with 1 c. c. virulent blood on the 14th
day and both developed severe attacks of the disease, one dying and the other very nearly so, showing that
no protection had been afforded. As it was afterwards found that Dr. Edington advises that only 0.2 c.c. of
blood should be used for the second inoculation, six other animals were inoculated with the dose of Glycerinated
bile recommended by him, taking into account the weight of the animals, and on the tenth day they were re-
inoculated with 0.2 c.c. in accordance with his directions; but five of them died of rinderpest and the other
was very ill. This method, then, does not appear to be successful in Indian hill cattle, but it will have to
be tested on the less susceptible plain ones in whom it may possibly give better results. As, however, in point
of susceptibility to the disease the Indian bill cattle are more on a par with the South African animals than
are the Indian plain cattle, the results so far obtained are disappointing, and it appears to be an example of
the differences among various breeds of cattle with regard to the ease or difficulty of affording them protection
from the disease by various methods.
"Liver extracts.—As the protective substance in rinderpest bile, whatever it may be, must be secreted by
the liver, it seemed possible that it might also be present in the liver substance after death in perhaps still
larger quantities, and in that case, if it could be made use of for protective inoculation, the number of cattle
that might be protected from material obtained from one rinderpest animal, might be materially increased.
It was recognised that the liver would also contain a large amount of the infective material, but it was hoped
that this might be eliminated either by keeping it for some time or by filtering the liver extracts through a
Pasteur filter.
"An animal was first inoculated with a dose of the extract from the liver of an animal which had died of
rinderpest and which had been kept for three days in ice, and, as was expected, rinderpest ensued and proved
fatal. Another animal was inoculated with a dose of the same liver extract which had been kept in ice for
eleven days.
"Rinderpest again ensued and caused death. Two other animals were inoculated with different doses of
liver extract which had been passed through a Pasteur filter. No reaction ensued, and on inoculating one with
virulent blood subsequently, and exposing the other to natural infection, both took the disease severely and one
of them died. The unfiltered extract, then, produced the disease after being kept for eleven days, while the
filtered extract produced little or no protection. The results of the use of filtered bile mentioned above ex-
plains the failures to obtain protection in this latter way.
"Bile from a salted animal.—An animal which had been protected by the simultaneous method of inocula-
tion and had subsequently received increasing doses of virulent blood, the last being 500 c.c., unfortunately
died of acute Bright's disease, so the opportunity was taken to test if his bile contained any antitoxic
properties.
"An animal was therefore inoculated with 50 c.c. of the bile on one side of the body and 1 c.c. of viru-
lent blood on the other side, after the method of simultaneous inoculation. The animal contracted a virulent
attack of the disease and died. As, however, the beast was a hill one, which it was subsequently found require
a very much larger dose of serum, weight for weight, than do plain cattle, the quantity of bile used was not as
great as would have been required of the serum of the same animal at this stage of salsing, to have certainly
protected a hill animal from the disease; so this experiment cannot be taken to prove that the bile of a salted
animal does not contain the protective material.
"Another animal was injected with 20 c.c. of the same bile as that used in the last experiment, but no
protection was afforded by it. It appears from this that, although the animal from which the bile was taken
had a very fair temperature reaction after he was injected with 500 c.c. of virulent blood, but showed no
symptoms, nevertheless, no very active protective material was being secreted by his liver as occurs during an
actual attack of the disease. As it had been found that during the course of these injections of virulent blood
into immune animals, their blood contains the active infective material, as shown in experiments mentioned in
para. 24 by its injection into a healthy animal producing the disease, it might have been thought that the bile
would have contained the protective material, but this appears not to be the case. The point is, however, only
of theoretical importance, as such animals are far too valuable as serum producers to be available for
furnishing bile.
"Preservation of he infection in blood.—These experiments were undertaken partly to see if any attenua-
tion of the virus could be obtained and partly to see how long the virus could be preserved in blood from an
infected animal kept under different conditions.
"A small quantity of blood was placed in a glass bulb, and hydrogen gas having been passed through the
tube to expel all the air, it was sealed up and kept at the room temperature, which at that time was only from 4
to 10 centigrade. Some of the same blood was put up in a similar tube from which the air was not expelled
before it was sealed up. In the first experiment, blood which had been thus put up four days after it was
obtained from the animal, and kept for eleven days more under the same conditions, was used, and both that in-
hydrogen and the control blood in air produced a severe and fatal attack of the disease. In a second experiment
with the same blood which had been kept under the conditions noted for twenty days, the result was negative, but
in a third series, blood which had been put up in hydrogen for nineteen days caused a severe and fatal attack
of rinderpest when injected subeutaneously, but some of the same blood which had been sealed up without
removing the air gave the same result:
"It appears, then, that hydrogen gas had no effect either in preserving or in attenuating the virus over
ordinary air. The length of time which the blood remained virulent was also uncertain, but might be consider-
able, and as it has recently been found that difficulty is sometimes met with in villages in getting the consent
of the people to allow the small quantity of virulent blood that is required for the simultaneous method of
inoculation to be taken from any of their sick cattle, these experiments will be continued; for, if a method of
preserving the virus for two or three weeks without loss of virulence can be discovered, it may be found possible
to keep such a supply of virulent material at the Bareilly experimental station when that place is completed.
Dried rinderpest blood is also being tested.
"Inoculation of blood from animals in different stages of salting.—In the process of making protective
serum large doses of virulent blood in increasing quantities are injected into animals which have recovered from
the disease, with the result that only a temperature reaction without symptoms is produced. It appeared to be
likely that the virus was modified in some way in this process, and although it was probable that its intensity
would be increased on account of the resistance that it would meet with from the antitoxine or other protective
substances already produced in the animal's body by its reaction to the virus, rather than reduced, yet the
question seemed to be worth testing.
"A series of animals were therefore inoculated with blood obtained from animals at different periods
after injections of large doses of virulent blood subcutaneously. It was found that, if the blood was taken
after the reaction was over and the temperature had fallen to normal, no effect was produced. If, on the other