NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
PREPARATION OF ANTI-RINDERPEST SERUM.
235
Result of Serum Testings. (B).
First Series.—
No. of
Bull.
380
355
363
366
388
392
Weight
in lbs.
192
216
263
208
341
352
Actual dose
of Serum
injected.
2.88 c.c.
3.24 „
7.89
„
8.04 „
20.46 „
21.12 „
Rate of
Serum
testing per
600 lbs.
9 c.c.
9 „
18 „
18 „
36 „
36 „
Result.
H. T. R. Vesicles 6th day. Ulcers
7th day. On 10th day died.
No T. R. Vesicles 7th day. Ulcers
8th day. On 10th day died.
H. T. R. Vesicles 7th day. Ulcers
8th day. On 11th day died.
F. and M. animal. Vesicles 7th day.
On 7th day died.
H. T. R. Vesicles 8th day. Ulcers
9th day. On loth day died.
Slight T. R. Vesicles 9th day. Ulcers
10th day. Recovered.
Second Series of Serum Testing. (B).—
No. of
Bull.
425
416
417
410
439
421
Weight
in lbs.
129
132
137
154
167
194
Actual dose
of Serum
injected.
15.48 c.c.
15.83 „
24.66 „
27.74 „
40.08 „
46.56 „
Rate of
Serum
testing per
600 lbs.
72 c.c.
72 „
108 „
108 „
144 „
144 „
Result.
Slight T. R. Vesicles 8th day. Ulcers
9th day. Recovered.
Slight T. R. Vesicles 8th day. Ulcers
9th day. Recovered.
Slight T. R. Vesicles 6th day. Ulcers
9th day. Recovered (Foot and Mouth).
Slight T. R. No lesions. Recovered.
No. T. R. No Lesions Died of weak-
ness 14th day.
Slight T. R. No lesions. Recovered.
Summary of Serum Testings.—
Two Bulls tested at 9 c.c. ..
„ 18 „
..
„ 36 „
..
„ 72 „ ..
„ 108 „
..
„ 144 „
..
Both died.
Both died.
One died on loth day ; one recovered.
Both recovered.
Both recovered.
One recovered; one died 14th day of weakness.
Approximate Protective dose of Serum B = 90 c.c.
Serum C.—
Serum prepared as follows :—Peritoneal fluid pipetted
out from Peritoneal cavity of " Controls '' previously bled out.
236
PREPARATION OF ANTI-RINDERPEST SERUM.
Definite volumes of peritoneal fluid added to a definite volume
of potassium citrate 0.5% solution.
Three Bulls used. 5359—Age
5365— „
5375— „
3 years—Weight 221 lbs.
3 „ — „
206 „
10 „ — „
303 „
Immunised with serum and virulent blood ..
Injected with 350 c.c. Peritoneal Fluid (plus 1150 c.c. Pot.
Cit.) .. .. .... .. .... .. ..
Injected with 500 c.c. Peritoneal Fluid (plus 1500 c.c. Pot.
Cit.).. .. .... .. .... .. ..
Bled for serum
Serum from 5359, 5365 and 5375, mixed and tested.
November 26th, 1910.
January 3rd, 1911.
January 20th, 1911.
December 17th, 1910.
Result of Serum Testing. C.—
No. of
Bull.
444
423
414
452
411
426
Weight
in lbs.
125
149
137
150
159
194
Actual dose
of Serum
injected.
22.50 c.c.
26.80 „
32.88 „
36.00 „
57.24 „
69.84 „
Rate of
Serum per
600 lbs.
108 c.c.
108 „
144 „
144 „
216 „
216 „
Result.
H. T. R. Vesicles 6th day. Ulcers
7th day. On 10th day died.
H. T. R. Vesicles 6th day. Ulcers
7th day. On 15th day died (F. & M).
H. T. R. Vesicles 7th day. Ulcers
9th day. Recovered.
H. T. R. Vesicles 7th day. Ulcers
8th day. On 14th day died.
Slight T. R. No Vesicles. Recovered
(F. & M.).
H. T. R. Vesicles 7th day. Ulcers
8th day. Recovered (F. & M.).
Summary of Serum Testings—
Two Bulls tested at 108 c.c.
„ „ „ 144 „
„ „ „ 216 „
..
..
..
Both died.
One recovered; one died.
Both recovered.
Approximate Protective dose of Serum C=216 c.c.
Serum D.—
Serum prepared by two injections of defibrinated virulent
blood diluted with potassium citrate 0.5%.
Bulls used. 5366—Age
5367— „
5373— „
5376— .,
10 years—Weight 240 lbs.
8
„ — „
257 „
2¾ „ — „ 196 „
3
„
— „
168 „
Immunised by serum and virulent blood
Injected with 300 c.c. V. B. (plus 1200 c.c. Pot. Cit.)
..
„ 500 „ „ ( „ 1500 „ „ „)
Bled for serum
Serum from 5366, 5367, 5373, 5376, mixed and tested.
November 26th, 1910.
December 15th, 1910.
December 31st, 1910.
January 17th, 1911.
PREPARATION OF ANTI-RINDERPEST SERUM.
237
Result of Serum Testing. D.—
No. of
Bull.
454
449
409
451
437
420
Weight
in lbs.
135
135
150
159
159
185
Actual dose
of Serum
injected.
24.30 c.c.
24.30 „
36.00 „
36.10 „
57.24 „
66.60 „
Rate of
Serum
testing
per 600 lbs.
108 c.c.
108 „
144 „
144 „
216 „
216 „
Result.
H. T. R. Vesicles 8th clay. Ulcers 9th
day. On 9th day died.
H. T. R. Vesicles 6th day. Ulcers 7th
day. On 9th day died (F. & M.).
H. T. R. Vesicles 7th day. Ulcers 8th
day. On 10th day died (F. & M.).
H. T. R. Vesicles 9th day. Ulcers
10th day. Recovered.
H. T. R. Vesicles 9th day. Ulcers 10th
day. On 12th day died (F. & M.).
H. T. R. Vesicles 9th day. Ulcers
10th day. Recovered (F. & M.).
Summary of Serum Tests. D.—
Two Bulls tested at 108 c.c.
„ „ „ 144 „
„ „ „ 216 „
..
..
..
Both died.
One recovered ; one died
One recovered ; one died.
Approximate Protective dose of Serum D = 216 c.c.
Serum E.—
This serum was prepared by two injections of virulent
blood run directly from the vein of the " Control " into potas-
sium citrate solution.
Four Bulls used. 5357—Age 4½ years
5361— „ 3 „
5362— „ 4½ „
5363— „ 12
„
—
—
—
Weight 225 lbs.
„ 193 „
„ 214 „
„ 252 „
Immunised by means of Serum and Virulent blood
Injected with 300 c.c. V. B. run directly into 1200 c.c. Pot. Cit.
„ „ 500 c.c. V. B. run directly into 1500 c.c. Pot. Cit.
Bled for serum
—
January 17th, 1911.
November 26th, 1910.
December 15th, 1910.
December 31st, 1910.
Serum from 5357, 5361, 5362, 5363, mixed and tested.
Result of Testing Serum E.—
No. of
Bull.
455
431
Weight
in lbs.
135
150
Actual dose
of Serum
injected.
24.30 c.c.
26.10 „
Rate of
Serum
testing
per 600 lbs.
108 c.c.
108 „
Result.
H. T. R. No Lesions. Weak. Died
8th day (F. & M.).
H. T. R. Vesicles 8th day. Ulcers
9th day. On 11th day died. (F. & M.).
238
PREPARATION OF ANTI-RINDERPEST SERUM.
Result of Testing Serum E.—(Contd.)—
No. of
Bull.
447
438
445
422
Weight
in lbs.
159
159
176
181
Actual dose
of Serum.
injected.
38.16 „
38.16 „
63.36 „
65.16 „
Rate of
Serum
testing
per 600 lbs.
144 c.c.
144 „
216 „
216 „
Result.
H. T. R. Vesicles 7th day. Ulcers
8th day. Recovered (F. & M.).
H. T. R. Vesicles 7th day. Ulcers
8th day. On 10th day died.
Slight T. R. No Lesions. Recovered.
(F. & M.).
H. T. R. Vesicles 6th day. Ulcers
8th day. Recovered (F. & M.).
Summary of Serum Tests. Serum E.—
Two Bulls tosted at 108 c.c.
„ „ 144 „
„ „ 216 „
Both died.
.. One recovered ; one died.
.. Both recovered.
Approximate Protective dose of Serum E = 216 c.c.
Massed Summary of Serum Tests.—
No. of
Serum.
A
B
C
D
E
How Prepared.
Two injections of peritoneal washings—("Routine Perito-
neal Washings'').
Two injections of defibrinated virulent blood—("Routine
V. B.")
Two injections of (Peritoneal Fluid plus Pot. Cit. 0.5%)
Two injections of (defibrinated V. B. plus Pot. Cit. 0'5%)
Two injections of (V. B. direct plus Pot. Cit. 0.5%)
Approximate
Protective dose
per 600 lbs. Hill.
50 c.c.
90 „
216 „
216 „
216 „
GENERAL RESULTS.
1. The tests shew that the seras prepared by the routine
method are potent seras, while those prepared by the injection
of diluted virulent material, Peritoneal Fluid or Virulent Blood,
are seras of low potency.
2. In this series the serum prepared by the routine '' Peri-
toneal Washings '' method is more potent than that made by
the routine '' Virulent Blood '' method. The results are
in accord with those obtained in the Philippine Islands,
but different from those previously obtained in this
Laboratory. Previous testings in this Laboratory have
PREPARATION OF ANTI-RINDERPEST SERUM.
239
shewn that the P. F. serum has about half the potency of
V. B. serum.
3. By comparing the potency of Serum A and Serum C,
it will be seen that C is only one-quarter, or perhaps one-fifth,
as potent as Serum A, and these results suggest that some other
process than simple dilution of the pre-existent Peritoneal
Fluid occurs, when a control is injected with Potassium Citrate
Solution and the Peritoneal Washings subsequently withdrawn.
That is. the Peritoneal Washings prepared in vivo are more
virulent, or contain more virus than those prepared in vitro,
and a greater production of Rinderpest Immune Bodies
follows the injection of the former than the latter.
4. Seras D and E are practically the same.
In the case of Serum D, the V. B. was defibrinated.
In the case of Serum E, the V. B. was not defibrinated,
but ran straight from the vein into Pot. Cit. Solution.
In both cases seras of low potency were obtained, the
strength of the seras being comparable to the strength of
Serum C, also prepared by a dilution method.
It may be noted here that the injection of the above
volumes of. diluted virulent material into the serum-making bulls
caused no rise in temperature, and it would appear that the
result of the two injections (1,500 c.c. and 2,000 c.c.) was mere-
ly to neutralise the Immune Bodies formed in the blood as a
result of immunisation. The amount of virus injected (always
at a positive phase) was not sufficient to stimulate the produc-
tion of more immune bodies. From the result of the tests of
Seras C, D and E it may be concluded that the injection of
virulent fluids, diluted in the proportion of (300 : 1,200) and
500 : 1,500) the injections being made at a positive phase, has a
deleterious effect on the resulting serum.
In another part of this Memoir experiments are described
by the Imperial Bacteriologist on the preparation of Rinder-
pest Anti-Serum by means of the injection of diluted virulent
blood. The only point of similarity between these two series
of experiments is that the virulent blood was diluted with
240
PREPARATION OF ANTI-RINDERPEST SERUM.
Potassium Citrate prior to injection. In the experiments
described above it is to be noted :—
1. That susceptible Hill Bulls were used throughout.
2. That two massive injections were given, each at a
positive phase. The only change from the routine method
adopted in the preparation of the seras C, D and E was the
substitution of diluted fluids for defibrinated virulent blood.
The intervals between the various injections and bleeding
were the same as those adopted in the routine method of serum
making.
3. The virulent blood and peritoneal fluid were diluted
to the extent of 1 in 5.
In the experiments referred to above, carried out by the
Imperial Bacteriologist at Bareilly—
1. Plains Bulls and Buffaloes were used.
2. The greater number of the massive injections were
made at a negative phase. A certain number of seras were
prepared by positive phase injections and by multiple injections,
and it was clearly demonstrated that in animals of lower sus-
ceptibility, positive phase injections and multiple injections
result in the production of seras of relatively low potency.
3. In making the dilutions of virulent material for injec-
tion, equal parts of blood and Potassium Citrate solution were
taken.
From the results of these experiments on the effect of dilu-
tion on the potency of the resulting serum, it is clear that the
dilution of one in five adopted is too great. The results of the
experiments on plains bulls and buffaloes suggest that in the
preparation of serum from hill bulls—
1. The first massive injection should be given, as soon as
possible, after the immunising injection of serum and virus.
Owing to the greater susceptibility of. hill animals injections
during the negative phase are probably not practicable.
2. That one massive injection is preferable to two.
3. A dilution of equal parts of virulent blood and
Potassium Citrate should be adopted.
PREPARATION OF ANTI-RINDERPEST SERUM.
241
Recently, serum from hill bulls has been prepared on the
lines indicated in (1), (2) and (3) above with most encourag-
ing results. As far as can be seen at present serum prepared
on these lines is superior in potency to that prepared by the
older methods, viz., by repeated massive injections of defibrin-
ated virulent blood at positive phases.
16
PART
III.
HÆMORRHAGIC SEPTICÆMIA.
FURTHER TESTINGS OF THE HÆMORRHAGIC SEP-
TICÆMIA ANTI-SERUM AND VACCINE.*
BY
MAJOR J, D. E. HOLMES, M.R.C.V.S., M.A., D.Sc., I.C.V.D.,
Imperial Bacteriologist to the Govt. of India.
In a previous publication (C. V. D. Memoirs, No. 1), I
described the methods of preparation of a serum and dead
vaccine against Hæmorrhagie Septicæmia of Bovines. The
results of the experimental tests carried out in the Laboratory
shewed that the serum in a dose of 5 to 10 c.c. protects cattle
against a lethal dose of virus inoculated 24 to 48 hours after
the serum and that an injection of 25 c.c. serum gives a pro-
tection for a period of about four weeks. The vaccine in a
dose of 5 c.c. protects against a lethal dose of virus inoculated
four days after the injection of the vaccine. The immunity
following a dose of vaccine in amounts of 5 to 10 c.c. persists
for a period of about six weeks.
During the past two years, 1,825 doses of this Anti-Serum
and 63,810 doses of the Vaccine have been issued for use in
the field, and as far as it was possible to trace, the results have
been satisfactory. The Superintendent, Civil Veterinary
Department, C. P., in his letter No. 343-20, dated 11th February
* Results arrived at in July 1911.
HÆMORRHAGIC SEPTICÆMIA.
243
1910, to the Inspector-General, Civil Veterinary Department,
stated :—'' The results appear to me to be remarkably good,
sufficient time has not yet elapsed to pronounce with absolute
certainty of the result, but I forward the appended table to
shew what is up to now so satisfactory.''
" The Superintendent, Civil Veterinary Department, U.
P., in his letter No. 860/154A-1, dated 23rd March 1909, to the
Inspector-General, Civil Veterinary Department, reported:—
that he tried the vaccine in an outbreak in which 10
animals had died in 2 days and 4 were sick. One hundred
healthy animals were vaccinated and the village kept under
observation for three months, but no deaths were reported,
except two sick animals (uninoculated) during that
interval.
During the winter of 1909 at Bareilly an outbreak of
Hæmorrhagic Septicæmia occurred among a small batch of
18 hill bulls in the Laboratory. Eleven of these were treated
with 10 c.c. each of the serum. Four deaths took place before
the use of serum. Three more non-treated bulls died. Out
of the animals injected with serum, three shewed high tem-
peratures and swellings at the throat but recovered. None
died.
In the Laboratory from time to time as occasion offered
the Hæmorrhagic Septicæmia serum and vaccine has been fur-
ther tested on ponies, mules, buffaloes and rabbits, and the
results confirm those recorded earlier.
The serum used in these experiments was prepared by the
method described for Serum D. (Memoir No. 1). Hill Bulls
were immunized by an injection of anti-serum followed by an
inoculation of 0.1 c.c. virulent culture 48 hours after. These
bulls were re-injected at intervals of 10 to 14 days with increas-
ing amount of virulent culture of Hæmorrhagic Septicæmia.
They received four injections, of amounts from 5 c.c. and
increasing to 2,000 c.c. The serum was first tested on Bulls.
The virus was a 48 hours culture of the Hæmorrhagic
Septicæmia organism.
244
HÆMORRHAGIC SEPTICÆMIA.
BULLS.
Serum and virus after 48 hours.
No.
Plains Bulls 1
„ „2
„ „ 3
„ „4
„ „5
Dose of
Serum.
5 c.c.
10 „
10 „
15 „
20 „
Dose of
Virus.
0.1 c.c.
0.1 „
0.1 „
0.1 „
0.1 „
Results.
Died in 50 hours.
Lived. No reaction.
„ „ „
„
Temperature reaction.
„
No reaction.
One Control died in 40 hours.
10 c.c. of this serum was protective against the virus
inoculated 48 hours after.
BUFFALOES.
Serum and virus after 48 hours.
No.
Plains Buffaloes 1
2
3
Dose of
Serum.
20 c.c.
25 „
25 „
Dose of
Virus.
0.1 c.c.
0.1 „
0.1 „
Lived.
„
„
Results.
No reaction.
„ „
One Control died in 30 hours.
The serum in a dose of 20 c.c. protects buffaloes against
the virus inoculated 48 hours after.
BUFFALOES.
Serum, plus virus after four weeks.
No.
Plains Buffaloes 1
2
3
4
5
6
7
8
9
Dose of
Serum.
5 c.c.
5 „
10 „
10 „
25 „
25 „
25 „
25 „
25 „
Dose of
Virus.
0.1 c.c.
0.1 „
0.1 „
0.1 „
0.1 „
0.1 „
0.1 „
0.1 „
0.1 „
Results.
Died 24 hours.
Lived. No reaction.
„ „ „
Died 30 hours.
Lived. No reaction.
„ „ „
„ „ „
„ „ „
„ „ „
Two Controls died within 30 hours.
The serum in a dose varying from 10 to 25 c.c. confers
an immunity for a period of about four weeks,
HÆMORRHAGIC SEPTICÆMIA.
245
BUFFALOES.
Vaccine, plus virus after four weeks.
No.
Buffaloes 1
„ 2
„ 3
„ 4
„
5
„ 6
Dose of
Vaccine.
5 c.c.
5 c.c.
5 c.c.
10 c.c.
10 c.c.
10 c.c.
J)ose of
Virus.
0.1 c.c.
0.1 c.c.
0.1 c.c.
0.1 c.c.
0.1 c.c.
0.1 c.c.
Results.
Died 30 hours.
Lived. No reaction.
Do.
Do.
Do.
Do.
Do.
Do.
Died 2 days.
The vaccine in a dose of 5 to 10 c.c. gives an immunity
for about four weeks.
PONIES
Serum, plus virus after 48 hours.
No.
Pony 1
„
2
„
3
„
4
„ 5
„ 6
Dose of
Serum.
5 c.c.
10 c.c.
10 c.c.
15 c.c.
15 c.c.
20 c.c.
Dose of
Virus.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
I c.c.
Results.
Lived. No reaction.
Lived. Temperature reaction.
Lived. No reaction.
Do.
Do. do.
Do.
Do. do.
Died in 3 days.
One Control died in 26 hours.
The serum in a dose of 5 c.c. upwards protects against
the virus inoculated 48 hours after.
PONIES
Serum, plus virus after four weeks.
No.
Pony 1
„ 2
„ 3
„ 4
„
5
Dose of
Serum.
5 c.c.
5 c.c.
10 c.c.
15 c.c.
20 c.c.
Dose of
Virus.
0.1 c.c.
0.1 c.c.
0.1 c.c.
01 c.c.
0.1 c.c
Results.
Died 56 hours.
Lived. No reaction.
Do.
High temperature reaction.
Do.
Temperature reaction.
Do.
No reaction.
One Control died in 40 hours.
The serum in a, dose varying from 10 to 20 c.c. protects
for a period of about four weeks.
246
HÆMORRHAGIC
SEPTICÆMIA.
PONIES.
Vaccine, plus virus after four weeks.
No.
Pony 1
„
2
„
3
„
4
Dose of
Vaccine.
5 c.c.
10 c.c.
10 c.c.
15 c.c.
Dose of
Virus.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
Results.
Lived. High temperature reaction
for 3 days.
Lived. No reaction.
Do.
Temperature reaction.
Do.
No reaction.
One Control lived, one Control died in 2½ days.
The vaccine in a dose varying from 5 to 15 c.c. confers an
immunity for a period of about four weeks.
MULES.
Vaccine, plus virus after four weeks.
No.
Mule 1
„
2
„
3
„
4
„ 5
„ 6
„ 7
„
8
„
9
„ 10
Dose of
Vaccine.
5 c.c.
5 c.c.
5 c.c.
5 c.c.
15 c.c.
15 c.c.
15 c.c.
15 c.c.
15 c.c.
15 c.c.
Dose of
Virus.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
Results.
Lived. Temperature reaction.
Died 36 hours.
Died 2 days.
Lived. Temperature reaction.
Lived. No reaction.
Do.
Do.
Do.
Do.
Lived. Temperature reaction.
Lived. No reaction.
Died 4 days.
The vaccine in a dose varying from 5 to 15 c.c. confers
an immunity for a period of about four weeks.
RABBITS.
Vaccine, plus virus after two weeks.
No.
Rabbit 1
„2
„3
„4
„
5
„ 6
„ 7
„ 8
„ 9
„ 10
„
11
Dose of
Vaccine.
1 c.c.
1 c.c.
1 c.c.
1 c.c.
2 c.c.
2 c.c.
2 c.c.
2 c.c.
5 c.c.
5 c.c.
5 c.c.
Dose of
Virus.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
0.00001 c.c.
Results.
Died 24 hours.
Died 30 hours.
Lived.
Do.
Died 30 hours.
Lived.
Do.
Do.
Died 24 hours.
Lived.
Do.
HÆMORRHAGIC SEPTIOÆMIA. 247
CONCLUSIONS.
Hæmorrhagic Septicæmia Anti-Serum:—
(1) The serum confers an immediate protection
against the inoculated virus.
(2) The immunity following an injection of serum
was tested and found satisfactory up to four
weeks.
(3) The injection of a suitable dose of serum protects
in not less than 90% of cases. A small percent-
age of animals cannot be protected even by large
doses of serum.
(4) A potent serum gives immunity in doses which
vary according to the size and species of the
animal—
For cattle the dose varies from
For Buffaloes
„
„
„
For Ponies
„
„
„
For Mules
„
„
„
5 c.c. to 20 c.c.
20 c.c. and upwards.
5 c.c. to 20 c.c.
5 c.c. to 20 c.c.
As the serum is innocuous and as the period of immunity
is somewhat lengthened by increased doses, it is recommended
that except in cases of young animals and cattle under 300lbs.,
the full dose of 20 c.c. should be used.
HÆMORRHAGIC SEPTICÆMIA VACCINE.
(1) The vaccine is innocuous. In some cases the in-
jection caused a slight swelling at seat of inocula-
tion which disappeared in a few days.
(2) It confers protection against the inoculated virus
for a period of four to six weeks.
(3) The protection is not immediate. It sets in about
four days following the injection of the, vaccine.
(4) The vaccine protects in about 75% of cases.
(5) The dose of vaccine varies from 5 c.c. to 10 c.c.
according to the size of the animal. A like dose
appears to be required for cattle, buffaloes,
ponies and mules.
PART IV.
ANTHRAX.
THE PRACTICAL VALUE OF ANTHRAX
ANTI-SERUM AND
VACCINES.
PRELIMINARY
REPORT.*
BY
MAJOR J. D. E. HOLMES, M.R.C.V.S., M.A.. D.Sc., I.C.V.D.,
Imperial Bacteriologist to the Govt. of India.
IN almost all infective diseases it is a well established fact
that an animal which has recovered from one attack enjoys an
immunity against subsequent attacks of the disease. In most
instances this refractory state is of comparatively long duration,
lasting from some years to a life time.
In anthrax, however, the protection conferred by one at-
tack persists for a shorter period, probably never longer than
nine or twelve months. Certain animals, such as Algerian
sheep and white rats, possess a natural immunity to anthrax,
but this immunity is not complete. Algerian sheep may suc-
cumb to repeated inoculation of the virus and the immunity
of the white rat can be overcome by fatigue.
Frequently, a species is refractory to the inoculated virus
but very susceptible to the spontaneous evolution of the dis-
ease. Thus, cattle are susceptible to the disease by inges-
tion but resistant to inoculation. The horse is more susceptible
than cattle to subcutaneous inoculation but more rarely con-
tracts the intestinal form. In India cattle are extremely re-
sistant to the inoculated virus but susceptible to natural
* Results arrived at in July 1911.
ANTHRAX.
249
infection ; the sheep dies in two to three days from inoculation,
but no marked mortality among these animals from natural
infection has been recorded in this country. The Indian coun-
try-bred horse is more resistant to inoculation than the imported
English or Australian horse, and both breeds contract the in-
testinal and cutaneous form by natural infection.
In France the sheep is most attacked while it generally
escapes in Germany and England. Horses resist fairly well
in France and Central Europe, while they are most attacked
in Russia. Cattle are the usual victims in Germany and Eng-
land.
IMMUNISATION.
I. By means of attenuated cultures.
Pasteur (1) was the first to use weakened cultures for the
purpose of immunising against anthrax. He prepared his
' first vaccine ' by growing a culture in oxygen at a tempera-
ture of 107.6°F. to 109.4°F. for 24 days. A quantity of this
culture, the virulence of which is considerably reduced, is first
injected and after an interval of 10 to 14 days a culture of con-
siderably greater virulence is injected.
Many modifications of Pasteur's method of attenuating
cultures for the preparation of vaccines have since been prac-
tised. Chamberland and Roux (2) weakened the bacilli by
chemical agents, such as carbolic acid and bichromate of
potash.
The Pasteur method of vaccination has been practised for
many years in Europe and America with varying success. In
France, Austria and Russia, where the vaccines have been most
extensively used, the inoculations are said to have produced
a marked reduction in the mortality from anthrax and to have
been attended with few accidents. From Italy the reports are
less favourable. In England McFadyean (3) concluded from
a number of inoculation experiments that it would be inadvis-
able to introduce the Pasteur method into that country.
In America the results of these vaccines have not been