NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
58
IV.
CONTROL CASES.
TREATED CASES.
N u m b e r o f p a t i e n t s .
N u m b e r o f d e a t h s .
M o r t a l i t y p e r c e n t a g e .
N u m b e r o f p a t i e n t s .
N u m b e r o f d e a t h s .
M o r t a l i t y p e r c e n t a g e .
IV.
Condition of patients
throughout the
treatment.
Temperature.
Patients admitted
with temperature
above 99°F., who
lived for more
than 48 hours, and
in whom the tem-
perature, after the
first application of
treatment (or, in
controls, after ad-
mission), reached
maximum—
Within 24 hours
8
5
62.5
6
5
83.33
Later than 24
hours.
5
3
6 0 . 0
7
5
71.42
Pulse.
Patients admitted
with pulse above
100 i n a mi nut e
who lived for more
than 48 hours, and
in whom the num-
ber, after first appli-
cation of treatment
(or,in controls,after
admission), reached
maximum—
Within 24 hours
4
2
50.0
1
1
1 0 0
Later than 24
hours.
10
7
70.0
1 1
10
90.90
Respiration.
Patients admitted
with more than 28
per minute, who
lived for more than
48 hours, and in
whom the number
recorded, after first
application of treat-
ment (or,in control,
after admission),
reached maximum.
Within 24 hours
1
1
1 0 0 . 0 . . .
. . .
...
Later than 24
hours.
2
1
50.0
2
2
1 0 0 . 0
59
V.
Recovery cases (treated and controls) : average interval between application of
treatment or admission to hospital, and the time when (1) temperature, (2)
pulse, and (3) respirations became for the first time normal.
Control cases.
Treated cases.
Temperature
.
7. 20 days
7 days
Pulse .
.
.
9.32 ,,
6. 33 , ,
Respirations
.
6.66 „
6. 33 , ,
VI.
Amount of serum injected (subcutaneously) into the 20 patients.
Total of serum injected.
Initial dose injected
on admission.
Patient 1,
80 c.c. injected in the vicinity of bubo—died
.
40 c.c.
,, 2,
40 c.c. injected in the vicinity of bubo—died
. .
40 c.c.
,, 3,
240 c.c. injected in the vicinity of bubo—died
.
40 c.c.
,, 4,
200 c.c. injected in the vicinity of bubo—died
.
40 c.c.
,, 5,
40 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
,, 6,
120 c.c. injected in the vicinity of bubo—cured .
.
40 c.c.
,, 7,
160 c.c. injected in the vicinity of bubo—died
.
40 c.c.
,, 8,
60 c.c. injected in the vicinity of bubo—died .
.
40 c.c.
,, 9,
80 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
,, 10,
200 c.c. injected in the vicinity of bubo—died
.
40 c.c.
,, 11,
600 c.c. injected in the vicinity of bubo—died
from peritonitis due to iliac bubo
.
4 0 c . c .
,, 12,
340 c.c. injected in the vicinity of bubo—died
. .
4 0 c . c .
,, 13,
140 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
,, 14,
340 c.c. injected in the vicinity of bubo—cured .
.
40 c.c.
,, 15,
40 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
,, 16,
140 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
,, 17,
340 c.c. injected in the vicinity of bubo—cured .
40 c.c.
,, 18,
260 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
,, 19,
280 c.c. injected in the vicinity of bubo—died
.
40 c.c.
,, 20,
80 c.c. injected in the vicinity of bubo—died
.
.
40 c.c.
I 2
60
REPORT ON A SERIES OF 68 CASES OF PLAGUE TREATED WITH
ROUX' ANTI-PLAGUE SERUM.
By W. G. WEST, M.R.C.S. (Eng.), L.R.C.P. (Lond.), M.D. (Geneva),
Attached to the Plague Research Laboratory, Bombay.
T HE serum was sent from the Pasteur Institute, Paris, in the middle
of March 1904, by Dr. Roux, in response to a telegram from
Mr. Haffkine, and was received here in the beginning of the following month.
Twenty litres of serum were sent out in bottles containing 100 c.c. each,
secured by India-rubber caps and stoppers.
The experiment was in all its details planned by Mr. Haffkine, before his
departure from India, but the watching of the patients and administration of
the serum was carried out in hospital by the present writer.
The patients treated were those admitted to the Maratha Municipal Plague
hospital (under the care of Dr. N. H. Choksy) between the 8th of April and
the 5th of May 1904. Between these dates 160 cases were admitted, 80 were
placed in the serum group and 80 alternate cases in the control group. Twelve
patients of the serum group were either moribund or convalescent on admission
and were therefore not injected. These 12 cases, as well as the 12
corresponding control cases, have therefore been excluded from the 160 cases,
thus leaving a total of 68 cases on each side.
As regards the doses given, Professor Roux' recent recommendations
(vide page 63, Roux' letter) were as far as possible carried out, viz. : —
(i) Subcutaneously, large doses were injected, the initial dose for an adult
being in the large majority of cases 100 c.c. followed in 12 hours
by a similar quantity. The total quantity of serum injected
generally amounted to 300 c.c. and more.
(ii) Intravenously, the initial dose was in the greater number of cases
40 c.c., followed by another injection of the same quantity 12
hours later, the total quantity of serum injected intravenously
amounting generally to about 120 c.c.
Of the 68 serum-injected patients—
(a) 43 were injected only subcutaneously, the initial dose being (as
before mentioned) mostly 100 c.c. and the total up to 300 or
more, and in one case 700 c.c. Of these, 29 died, giving a
mortality of 67.44 per cent.;
61
(b)12 patients were injected both subcutaneously and intravenously,
the initial injection in these patients being done subcutaneously.
Of these, 8 died, giving a mortality percentage of 66.66 per cent.
and, lastly,—
(c)13 patients had initial injections into the veins of 40 c.c. followed
in 12 hours by another injection of the same quantity ; some
few of these cases were also injected subcutaneously, the total
quantity of serum injected amounting in some cases to 400 and
500 c.c. Of this group, 8 died, giving a mortality of 61.53 per cent.
Among the 68 cases treated by the serum, there were 45 deaths, whereas,
among the 68 cases not so treated (control cases), there were 41 deaths.
The serum cases thus show a death-rate of 66.17 per cent., whereas the
control cases have a death-rate of 60.29 per cent., a difference in favour of the
control cases of 5.86 per cent.
In studying the attached tables, the chief point appears to be—Were the
larger number of the more serious cases in the group of the serum-treated
patients or not ?
With regard to the general condition of the patient on admission ( vide
Table II), it will be noticed that there were ten patients in such a feeble condi-
tion that these were classed among the moribund in the serum group, whereas
there were only four such cases among the control group. But, on the other
hand, there were 16 cases in the control group admitted in a comatose condition,
all of whom died, whereas there were only six such among the serum cases. The
distinction between "comatose" and "moribund" patients, however, was one
difficult to settle in the hospital, and it seems better to amalgamate these two
headings. If this be done, we find 20 patients comatose and moribund on the
control side, and 16 similarly conditioned on the treated side.
Taken as a whole, then, the conditions were slightly against the non-treated
cases under this head.
With regard to the sex of the patient, it will be noted that the highest
mortality occurred on the side of the males; of these, the serum cases had a
preponderance, the figures being 54 and 48, respectively.
Also with reference to the age of the patient, the highest mortality occurred
in those patients of 46 years and over. In this group the serum cases had
five cases, the control cases one.
Then, again, with regard to the nationality of the patient, the highest morta-
lity occurred among the Goanese and Native Christians ; here the serum cases
had a preponderance of six cases, the numbers being 4 and 10, respectively.
Similarly with regard to the finding of microbes in the blood on date of
admission, the serum group had 19, while the control group had 8 only.
62
The method adopted for demonstrating microbes in the blood was as
follows :
A small capsule of blood was taken from the patient, sealed up and sent
to the laboratory.
This blood was then placed in a watch glass, mixed with sterile salt solution
and injected subcutaneously into a rat, by one of the laboratory officials.
When the rat died, an examination by spleen smear and culture from the
heart blood was made to ascertain the presence or absence of plague germs.
It is unfortunate that owing to pressure of work in the laboratory the
examination of the rats dying after injection could not be carried out in a regular
manner. Such entries as "rat decomposed" occur frequently in the records,
and it is therefore impossible to say that the ratio of 8 to 19 represents the true
proportion of septicæmic cases in the two groups.
As the cases were chosen impartially, it seems incredible that such a large
proportion of septicæmic cases should have found their way into the serum
group. But the fact remains that this is so, and it must be kept in mind in
reckoning the results of treatment in this series of cases.
All the tables appear to demonstrate that, although no reduction of the
mortality could be attributed to the treatment, yet life was prolonged in many
cases.
That the initial effect of the serum had the power of reducing the tempera-
ture, pulse and respirations would appear to be probable, vide Table III, but
this favourable initial effect was not maintained.
63
Copy of a letter from Professor Roux, Paris, to W. M. Haffkine, Esq., C.I.E.,
Director-in-Chief, Plague Research Laboratory, Bombay ; dated Paris, the
25th March 1904.
" MON CHER DR. HAFFKINE,
" En réponse à votre télégramme je vous ai fait expedier 10 litres de sérum
antipesteux en flacons de 100 c.c. Ce sérum a donné d'excellents résultats
à Marseille chaque fois que nous l'avons essayé et aussi au Brésil, en
République Argentine, et au Mexique. Ce dont il faut être bien convaincu
c'est que les grandes doses sont nécessaires. Les médecins veulent toujours
employer le sérum antipesteux comme ils employent le sérum anti-diphtérique
et ils n'ont que de mauvais effets.
" La peste et la diphtérie ne sont pas des maladies comparables et le sérum
antipesteux n'agit pas à la manière du sérum anti-diphtérique. Si vous voulez
guérir vos pestifères, injectez 100 c.c. en une seule fois et réitérez l'injection
dans les 12 heures. Ne craignez pas d'injecter en tout 300 et plus.
" L'injection intra-veineuse demande moins de sérum et est plus efficace.
Une première injection de 40 c.c. suivie d'une seconde de même quantité
quelques heures aprés suffit le plus souvent.
" Mais cette petite opération doit être faite avec soin ; il faut faire tièdir le
sérum, s'assurer qu'il n'y a pas trace de dépôt et pousser l'injection très
lentement en interrompant à la moindre gêne respiratoire. Les médecins re-
doutent ces injections intra-veineuses qui ont si bien réussi à Calmette et à
Salimbeni lors de l' épidémie de Porto.
" Vous serez bien aimable, mon cher Haffkine, de me dire ce qui arrivera de
vos essais de séro-thérapie pesteuse.
" Recevez, je vous prie, l'assurance de mes sentiments les meilleurs et les
plus dévoués."
(Sé.) DR. ROUX.
64
Analysis of Sixty-eight clinical charts of patients under treatment with
Roux serum.
I.
CONTROL CASES.
TREATED CASES.
Nu mb e r o f p a t i -
ents.
N u m b e r o f
d e a t h s .
M o r t a l i t y p e r -
c e n t a g e .
A v e r a g e s t a y i n
h o s p i t a l b e f o r ed
e a t h ( i n d a y s ) .
Nu mb e r o f p a t i -
ents.
Numbe r of
deaths.
M o r t a l i t y p e r -
c e n t a g e .
Average stay in
hospital before
death (in days).
I.
1 day
.
3
. . .
. . .
. . .
3
1
33.33
2
Previous history.
2 days
.
14
8
57.14
3.75
24
19
79.16
6.63
Patients stated to have
been ill before ad-
mission for—
3 days
.
31
23
74.19
3.13
19
12
63.15
3.33
More than
3 days.
20
10
50
7
20
13
65
13.30
Unknown time
...
. . .
. . .
. . .
2
...
. . .
. . .
Total of pati-
ents admit-
ted.
68
41
60.29
4.19
68
45
66.17
7.57
II.
II.
State on admission.
Drowsy
19
12
63.15
4.16
21
14
66.66
9.03
General condition of
patients included in
the trial who, on ad-
mission were—
Comatose or un-
conscious.
16
16
100
2.15
6
6
100
2.33
Moribund
.
4
4
100
50
10
1 0
100
1.40
Not in above
condition.
29
9
31.03
9.50
31
15
48.38
12.56
Below 99° F .
4
2
50
8.75
3
1
33.33
1.50
Temperature.
99°—100.9° .
13
7
53.07
1.85
15
1 0 66.66
6.65
Patients who had, on
admission,—
101°—102.9°29
21
72.22
3.52
31
20
64.51
8.81
103°—104.9°22
11
50
6.13
19
14
73.67
6.85
105° and above
...
...
...
. . . ...
...
. . .
. . .
Pulse-rate.
90 and below
3
1
33.33
2
1
. . .
. . .
. . .
Patients whose pulse-
rate, per minute, on
admission, was—
91—120
40
22
55
4.93
40
28
70
7.98
121—150
24
17
70.82
3.50
27
17
62.59
6.73
151 and above
1
1 100
3
...
. . .
. . .
. . .
65
II—continued.
CONTROL CASES.
TREATED CASES.
Nu mb e r o f p a t i -
ents.
N u m b e r o f
d e a t h s .
M o r t a l i t y p e r -
c e n t a g e .
A v e r a g e s t a y i n
h o s p i t a l b e f o r e
d e a t h ( i n d a y s ) .
N u m b e r o f p a t i -
e n t s .
N u m b e r o f
d e a t h s .
M o r t a l i t y p e r -
c e n t a g e .
A v e r a g e s t a y i n
h o s p i t a l b e f o r e
d e a t h ( i n d a y s ) .
II— contd.
Respirations.
Patients whose respira-
tions, per minute, on
admission, were—
35 and less
49
30
62.04
4.60
47
33
70.21
8.83
36—50
.
19
1 1
57.89
3.09
20
12
60
4.12
51 and above
. . .
. . .
. . .
...
1
. . .
. . .
. . .
Buboes.
Single .
.
...
...
. . .
. . .
. . .
. . .
. . .
. . .
Maxillary,
single.
...
...
...
. . .
. . .
...
...
...
Cervical, single
5
3
60
2.83
1
1
100
1
Patients in whom
buboes were found,
on admission or
later on, to be—
Parotid, single
...
. . .
...
. . .
2
1
50
2.50
Axillary,
single.
12
8
66.66
2.62
14
8
57.14
10.12
Iliac, single .
...
...
. . .
. . .
...
. . .
. . .
. . .
Inguinal,
single.
...
...
...
. . .
. . .
...
...
Patients in whom
buboes were found,
on admission or
later on, to be—
Femoral,
single.
2
2
100
2.50
1
...
...
. . .
Others, single
...
. . .
. . .
. . .
...
. . .
...
. . .
Multiple
.
. . .
. . .
. . .
...
...
...
...
. . .
Multiple,
neighbour-
ing.
36
23
63.88
3.10
38
28
73.68
5
Multiple,
opposite.
6
2
33.33
10.00
4
1
25
15
Multiple,
scattered.
7
3
42.85
15.33
8
6
75
1 6 . 5 0
Absent al-
together.
...
. . .
. . .
. . .
...
. . .
. . .
. . .
Sex, age, caste, and
nationality.
Both sexes
.
Males .
.
48
31
64.58
7.97
54
37
68.51
6.68
Females
.
20
1 0
50
3.85
14
8
57.14 11. 68
za
66
11 —concluded.
CONTROL CASES.
TREATED CASES.
N u m b e r o f p a t i e n t s .
N u m b e r o f d e a t h s .
M o r t a l i t y p e r c e n t a g e .
A v e r a g e s t a y u b h o s p i t a l b e f o r e d e a t h ( i n d a y s )
N u m b e r o f p a t i e n t s .
N u m b e r o f d e a t h s .
N u m b e r o f p e r c e b t a g e .
A v e r a g e s t a y u b h o s p i t a l b e f o r e d e a t h ( i n d a y s )
II —concld.
Sex, age, caste, and
nationality—contd.
Among the patients
there were—
Up to to years
of age.
8
5
62'50
5
5
2
40
23'25
11—25
•
37
23
62'16
4'71
36
22
61'11
5'61
26—45
•
22
12
54'54
3'1 2
22
17
77'27
8'26
46 and above
1
1 100
1
5
4
5
7'62
Hindoos•
53
34
64'15
4'20
51
34
66'66
8'73
Mahomedans
1 1
4
36'36
5'87
7
4
5114
2'62
Goanese and
Native Chris-
tians.
4
3
75
1'83
10
7
70
4'71
Parsis
. . . ...
. . .
. . .
...
. . .
. . .
. . .
E uropeans and
Eurasians.
...
...
. . .
...
...
...
. . .
...
Microbes in blood.
Patients in whom
microbes were found
to be—
Present on
date of ad-
mission.
8
8 100
2'12
19
19 100
2'84
Absent
52
23
53 . 86
3'56
41
21
51'21
8'23
Not examined.
8
5
62 .5
1 1
8
5
62'5
2280
o days
...
. . .
. . .
. . .
. . .
. . .
. . .
. . .
Patients in whose
blood plague bacilli
were discovered on
date of admission,
and who lived after
this for—
1 day
•
2
2 100
2
8
8 100
1'25
2 days
3
3 100
2.16
3
3
100
2'16
3 and a few
more days.
2
2 100
3'25
8
8
100
4'63
Recovered
. . .
...
. . .
. . .
...
. . .
. . .
6 7 .
CONTROL CASES.
TREATED CASES.
Number of patients.
T h e i r p r o p o t i o n t o t o t a l ( p e r c e n t . )
N u m b e r o f d e a t h s
M o r a l i t y p e r c e n t a g e .
A v e r a g e e x t e n t o f i n c r e a s e o r d e c r e a s e .
N u m b e r o f p a t i e n t s .
T h e i r p t o p o t i o n t o t o t a l ( p e r c e n t . )
N u m b e r o f d e a t h
M o r a l i t y p e r c e n t a g e .
A v e r a g e e x t e n t o f i n c r e a s e o r d e c r e a s e .
III .
Condition of patients after
first application of treat-
ment.
Duration of life.
Died within 24 hours of ad-
mission.
......
9 13.23
9 10
. . .
6
8 .82
6
1 0 0
. . .
Lived for more than 24 hours
......
59 86.76 32 54.23
...
62
91.17 39
62.90
...
Temperature.
Total of patients admitted
with 100ºF. and over, who
lived for more than 24
hours.
......
48 70 . 58 29 6o.41
...
55
80.88 36
65.45
...
Patients admitted with
more than 100°F., in
whom the next tempera-
ture, examined
after
treatment (or, in controls,
after admission), showed
an—
Increase
27 39.85 19 70.37
1.92 28
41.17
1 8
64.28
1.12
Decrease
27 39.85 16 59.25
1.58 29
42.64
21
72.41
2.03
Stationary
condition.
3
4.41
2
4.41
. . .
2
2.95
1
5 0
. . .
Pulse rate.
Total of patients admitted
with more than 100 in a
minute, who lived for more
than 24 hours.
......
57 83.82
8 2
47.05
...
6 0
88.23 37
61.66
...
Patients admitted with
more than too in a
minute, in whom the next
examination, after treat
ment (or, in controls,
after admission), showed
an—
Increase
31
45.58 21 61.74 8.22 25
36.76
20
8 0
8 . 1 2
Decrease
22 32.35 12 54.54
9.00 29
42.64
16
55.17 14.10
Stationary
condition.
13 19.11
8 53 84
...
1 1
16.17
6
54.54
. . .
Respirations.
Total of patients admitted
with more than 28 in a
minute, who lived for more
than 24 hours.
......
5o 73.52 26 52
...
59
86.76 26
44.06
...
Patients admitted with
more than 28 in a minute,
in whom the next exami-
nation, after treatment
(or, in controls, after ad-
mission), showed an—
Increase
19 27.94 14 73.68
5.10 20
29 .55 16
8 0
5
Decrease
28 41.17 14 50
3.32
26
38.23
12
46.15
6.03
Stationary
condition.
12
17.64
7 58.3
...
16
23.52
8
50
. . .
68
.
IV.
CONTROL CASES.
TREATED CASES.
N u m b e r o f p a t i e n t s .
T h e i r p r o p o r t i o n t o t o t a l ( p e r c e n t . )
N u m b e r o f d e a t h s .
M o r t a l i t y p e r c e n t a g e .
N u m b e r o f p a t i e n t s .
T h e i r p r o p o r t i o n t o t o t a l ( p e r c e n t . )
N u m b e r o f d e a t h s .
M o r t a l i t y p e r c e n t a g e .
I V .
Condition of patients
throughout the treat-
ment
Temperature.
Patients admitted with
more than 100°F., who
lived for more than 48
hours, and in whom
the temperature, after
the first application of
treatment (or, in con-
trols, after admission),
reached maximum.
Within 24
hours.
28
41.17
16
57.14
27
39.85
15
55.55
Later than
24 hours.
13
1 9 . 1 1
1 0
76.92
18
26.47
12
66.66
Pulse-rate.
Patients admitted with
more than 100 in a
minute, who lived for
more than 48 hours,
and in whom the rate,
after first application
of treatment (or, in con-
trols, after admission),
reached the maximum.
Within 24
hours.
31
45.58
12
38.70
27
39.85
1 1
40.74
Later than
24 hours.
16
23.52
10
62.50
24
35.29
1 8
75
Respirations.
Patients admitted with
more than 28 per
minute, who lived for
more than 48 hours,
and in whom the rate,
after first application
of treatment (or,in con-
trols, after admission),
reached a maximum.
Within 24
hours.
24
35.29
9
37.5o
21
30.88
8
38.09
Later than
24 hours.
23
33.82
1 5
65.21
28
44.17
17
60.71
Temperature.
Patients who ultimately
recovered, and who,
after their tempera-
ture had reached nor-
mal, had a rise t
above 99°F. within a
fortnight of their ad
-mission.
. . .
14
20.58
...
. . .
16
23.52
. . .
...
69
v.
Additional Information :—(I) The highest temperature, pulse and respiration of
all recovery cases (treated and control).
CONTROL CASES.
TREATED CASES.
Te mperature.
Pulse.
Respirations.
Temperature.
Pulse.
Respirations.
1 0 2 . 6
128
36
104.2
130
58
103
142
44
104
112
30
104
140
46
102.8
130
48
103
160
46
103
2 8
25
104.6
130
35
103
1 1 0
40
1 0 3 . 8
128
38
103.6
120
2 8
103.8
120
33
102
132
4 8
102.8
122
35
1 0 3 . 8
122
3 0
101.2
1 1 0
26
104.2
130
42
1 0 4 . 2
140
46
104
112
30
100
104
28
104.8
1 6 0
45
1 0 3 . 2
122
34
103.8
120
30
104
160
5 0
104.6
140
3 8
101.4
112
28
1 0 5 . 8
140
45
103.8
120
34
104
126
30
104
120
30
104
120
30
103
120
44
103.4
110
30
100
128
38
103.6
130
34
101.6
128
35
103
128
35
103
130
35
104.9
120
40
103.6
120
36
105
140
40
102.8
1 1 0
2 8
102
124
35
103
122
26
102
122
40
102.8
122
33
. . .
. . .
...
104
130
36
. . .
...
. . .
1 0 0
98
24
. . .
. . .
. . .
1 0 4 . 2
144
40
...
. . .
. . .
70
(2) The time (in days) when (1) temperature, (2) pulse, and (3) respirations
became for the first time normal, after the application of treatment or
admission into hospital (in days).
CONTROL CASES.
TREATED CASES.
Temperature.
Pulse.
Respirations.
Temperature.
Pulse.
Respirations.
8 . 4 2
9.20
9.02
6.24
8.40
7.04
(3) Average stay in hospital of fatal cases (in days).
Control cases.
Treated cases.
4.19
7.59
71
APPENDIX A.
Method of preparation of Lustig's Anti-Plague Serum, as employed by Drs. G. Polverini
and A. Mayr in the Bombay Municipal Laboratory at Parel, until May 1902.
By A. Mayr, M.D.
1. Cultures of B. pestis were made from the blood of plague patients. These were
grown on the ordinary 1 per cent. peptone agar in large glass dishes (10" diameter) for
2—3 days.
2. After macro-, and micro-scopical examination to ascertain the purity of the
growth, it was scraped off with a spatula and transferred to a glass beaker.
3. The mass obtained from the scrapings of 5 or 6 dishes was then mixed with about
100 c.c. of a one per cent. solution of caustic potash, and the whole well stirred until a
uniform mucilaginous solution was obtained. This was kept standing for half an hour to
make sure of its sterility, which was always controlled by culture at this stage.
4. To this was added with constant stirring one per cent. of acetic acid, until a
white flocculent precipitate was brought down. This was collected on a filter and washed
till free from acid. This precipitate which can be dried and kept for a considerable
time without deterioration, is the immunising substance, and is soluble in one per cent.
sodium carbonate solution.
5. When required for the immunisation of the horses, the immunising substance (in
most cases still moist) was dissolved in some sodium carbonate solution, and to this was
added as much 0.6 per cent. salt solution as would approximately make a concentration of
1 gramme of driedimmunising substancein 2,000 c.c. of fluid, for injection.
The amount of moist immunising substance required was known by experience, but in
order to calculate more exactly what the concentration was, 10 c.c. of the fluid, as used to
inject the horses, was placed in a graduated measure glass, and mixed with 5 c.c.
of the following solution :—
Mercuric chlorid
. .
.
.
.
.
. 7.0
Hydrochloric acid
. .
.
.
.
.
. 5. 0
Distilled water
.
.
.
.
.
.
. 100.0
This brought the immunising substance down again in the form of a white precipitate,
which on settling could be measured in the graduated glass. From the height to which
the immunising substance filled the glass, it was possible to calculate its weight in the
dried state from a table which had been worked out once for all.
6. One hundred c.c. of fluid for injection, equal to 0.05 gramme of dried
immunising substance, was usually injected into a horse subcutaneously the first time ; and
the injections were repeated about once a fortnight, the amount of immunising substance
being increased by about 2—3 centigrammes each time.
The serum was tested on animals from time to time, during the process of immunisa-
tion, and when found sufficiently active, the horse was bled. A horse was considered ready
for bleeding when 0.5 c.c. of serum protected a guinea pig of medium weight against
an infection from which the control animal died in 4—5 days. This standard was based