NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
14
in these tubes an attempt, if I might call it so, at neutralisation, but the venom
was still able to act on the plasma in a most decided manner. We can,
therefore, conclude that C. V. serum is, as far as this action is concerned,
practically specific.
I had not sufficient H. C. V. serum at my disposal to test it against
this action of these two venoms on plasma coagulability. As, however, the
primary action of the venom of Hoplocephalus curtus on the blood plasma is to
bring about a marked increase of coagulability, it is probable that the serum pre-
pared with this poison would be quite inactive against venoms, such as those
of the cobra and the king cobra, the primary action of which is to cause a dimi-
nution of blood coagulability.
It has long been known that many snake poisons, especially the venoms of the
Viperidæ, cause a marked primary increase of blood coagulability which often re-
sults in an extensive intravascular thrombosis. In the communication above referred
to, I showed that this action of these venoms on the blood plasma could be demon-
strated in vitro. Thus, it was shown that daboia venom clotted citrate plasma
without the addition of any salt of lime, and also that this poison markedly increased
the coagulability of oxalate plasma, but did not of itself cause solid clotting.
Since this publication I have investigated this phenomenon with the venoms of
several other species, and have found that this action of daboia venom on citrate
or oxalate plasma is slight in comparison with the similar action of four other
poisons, namely, the venoms of Hoplocephalus curtus, of Echis carinata, of
Trimeresurus gramineus and of Crotalus adamanteus. If a suitable amount of any
of these four venoms be added to either citrate or oxalate plasma, clotting takes
place almost instantaneously. Take, for example, the venom of Echis carinata,
the most powerful of these four poisons in this respect. Using 2 c.c. of citrate horse
plasma (1 per cent.) I found that 0.2 milligramme of venom caused a solid clot in
less than one minute, 0.02 milligramme in about ten minutes, 0.002 milligramme in
about one hour, and 0.0002 milligramme in at least 20 hours. If these results be
compared with the similar observations I have already published with regard to
daboia venom, it will be seen that the action of daboia venom on citrate plasma is
very much less marked than that of the poison of Echis carinata. Thus, 3
milligrammes of daboia venom caused a solid clot in 2 c.c. of citrate plasma
only after 3 hours, and 1 milligramme only after 20 hours. The other three
poisons mentioned above are intermediate between the venoms of Echis carinata
and Daboia Russellii in the following order of strength :—Crotalus adamanteus,
Hoplocephalus curtus and Trimeresurus gramineus.
The two sera under consideration were now tested against this action of
this group of poisons. The test dose of each venom used was such an one as
caused solid clotting of 2 c.c. of citrate horse plasma in from 5 to 13 minutes.
The following was the method employed in all instances. The test dose of
15
poison was mixed with varying amounts of either serum. The mixtures were
allowed to stand at laboratory temperature for half an hour. To each tube were
then added 2 c.c. of citrate plasma (1 per cent.). The results were noted at
intervals of one minute.
The details of the experiments with C. V. serum are given in Table XVII of
the protocols. From this table it will be seen that this serum had no hindering
effect at all on this action of any of the four venoms. The details of the experi-
ments with H. C. V. serum are given in Table XVIII of the protocols. A study of
this table will make it evident that this serum had a well-marked antagonistic
action for the corresponding venom, 0.06 c.c. of serum being able to prevent
the clotting caused by 0.1 milligramme of poison. On the other hand, it will be
seen that H. C. V. serum had no hindering effect at all on the actions of the
other three venoms.
We can, therefore, conclude that, as far as this action of snake poisons is
concerned, an antivenomous serum appears to be specific. As, however, the
serum prepared with Hoplocephalus curtus venom was not tested against the
venoms of any of the other Australian colubrine snakes, which have a similar
action on the blood plasma to that of the poison of Hoplocephalus curtus, it is
impossible to say that the serum is strictly specific in this action.
Protocols.
The two antivenomous sera, which were used in the observations detailed
below, were as follows.
(1) The serum of a horse which had been subjected for a period of two years
to repeated doses, gradually increasing in amount, of pure unheated cobra venom.
This serum is designated C. V. serum.
(2) The serum prepared by Dr. Tidswell of Sydney. 20This serum was
the serum of a horse which had been subjected to repeated doses, gradually
increasing in amount, of the pure unheated venom of Hoplocephalus curtus
(Australian tiger snake). This serum is designated H. C. V. serum.
In all the experiments to test the neutralising effect of the two antivenom-
ous sera on the general actions in vivo of the several venoms rabbits were the
animals employed. The test dose, a small multiple of the minimum lethal dose
either by subcutaneous or by intravenous injection, was mixed in vitro with
different amounts of one or other of the sera. The mixtures before injection were
allowed to stand at laboratory temperature for at least half an hour.
TABLE I.— Experiments to determine the neutralising power of C. V. serum for
the general action in vivo of pure unheated cobra venom.
The minimum lethal dose of the sample of venom used for a rabbit by sub-
cutaneous injection was 0.35 milligramme per kilo. The test dose now used was
about ten lethal doses.
16
The following were the results.
Animal.
Weight.
Cobra venom
in milligrammes.
C. V. serum.
Result.
Rabbit 1
.
. 710 grammes .
2
0.4 c.c.
.
. Died in 1¾ hours.
"
2
.
. 710
„
.
2
0.6 „
.
.
"
2¾
„
"
3
.
. 720
„
"
2
0.75 ,,
.
.
"
3
"
"
4
.
. 900
„
.
2
1
"
.
.
" 48
"
"
5
.
. 700
"
.
2
1
"
.
.
Recovered.
"
6
.
. 770
,,
.
2
1.2 "
.
. No symptoms.
"
7
.
. 740
"
.
2
1.25 ,,
.
.
"
" 8
.
. 880
„
.
2
1.25 „
.
.
"
"
9
.
. 700
„
.
2
1.5 "
.
.
"
"
10
.
. 740
,,
.
2
1.75 "
.
.
"
The maximum non-lethal dose for a rabbit of 770 grammes in weight (Rabbit
No. 6) can be taken at 0.2 milligramme. We can therefore calculate that 1.2 c.c.
of serum neutralised at least 2 –0.2= 1.8 milligrammes, and that 1 c.c. would be
able to neutralise 1.5 milligrammes of pure unheated cobra venom.
TABLE II.—Experiments to ascertain if C. V. serum has any neutralising
power for the venom of Naia bungarus (King Cobra).
The minimum lethal dose of the sample of venom used was about 0.35 milli-
gramme per kilo by subcutaneous injection. The test dose now used was about
ten lethal doses.
The following results were obtained.
Animal.
Weight.
N. B . V .
in milligrammes.
C. V. serum.
Result.
Rabbit 1
.
. 700 grammes
.
2
1.6 c.c. .
. Died in 5 hours.
„
2
.
. 750
"
.
2
2
"
.
.
"
8
"
"
3
. . 780
"
.
2
3
"
.
.
Found dead after 11 hours.
"
4
.
. 690
"
.
2
4
"
.
. Died in 8 hours.
"
5
.
. 840
"
.
2
5 "
.
.
Found dead after 11 hours,
"
6
. . 610
"
.
2
1 0
"
.
. Died in 31 hours.
"
7
.
. 700
"
.
2
14
"
.
.
"
31
"
„
8 (Control) . 750
"
.
2
Nil
.
.
„
1 h o u r .
17
It is evident from these experiments that 14 c.c. of serum failed to neutralise
2–0.2 17=1.79 milligrammes of venom. Therefore 1 c.c. could not neutralise
0.13 milligramme.
TABLE III.—Experiments to ascertain if H. C. V. serum has any neutralising
power for the venom of Naia bungarus.
The same sample of venom and the same technique were used as in the
previous series of experiments.
The following were the results.
Animal.
Weight.
V.
B.
N.
in
milligrammes H.C.V. serum. Normal serum.
Result.
Rabbit 1 .
.
. 680 grammes .
2
4 c.c.
. Nil
. Died in 3½ hours.
"
2 .
.
.
780
„
..
2
Nil
.
4 c.c.
.
"
3 ½
"
"
3 (control)
. 660
,,
.
2
Nil
. Nil
.
,,
1 hour.
It is evident that this serum has no neutralising power for the venom of Naia
bungarus.
TABLE IV.—Experiments to ascertain if either C. V. serum or H. C. V. serum
has any neutralising power for the venom of Bungarus cceruleus.
The test dose of venom used was 10 lethal doses by intravenous injection,
namely, 0.4 milligramme per kilo.
The following results were obtained.
Animal.
Weight.
B. C. V. in
milligrammes
per kilo.
C. V. serum. H. C. V. serum.
Result.
Rabbit 1 .
.
. 970 grammes .
0.4
4 c.c.
. Nil
. Died in 1 hour.
"
2
.
.
.
900
„
.
0.4
Nil
. 4 c.c
,, 47 minutes.
3 (control)
. 1,090
„
.
0. 4
Nil
. Nil
.
"
48
It is evident that neither serum has any neutralising power for the venom
of Bungarus cœruleus.
D
18
TABLE V.—Experiments to ascertain if C. V. serum has any neutralising
Power for the venom of Bungarus fasciatus.
The test dose of venom used was about 3 lethal doses, namely, 2 milligrammes
per kilo, by intravenous injection.
The following results were obtained.
Animal.
Weight.
B. F. V.
in milligrammes
per kilo.
C. V. serum.
Result.
Rabbit 1 .
.
. 1,050 grammes .
2
4 c.c.
.
. Died in 21 hours.
„
2 (control)
850
„
.
2
Nil .
.
.
"
26
„
It is evident that this serum has no neutralising power for the venom of Bun--
garus fasciatus.
TABLE VI.—Experiments to ascertain V C. V. serum has any neutralising
power for the venom of Enhydrina valakadien.
The test dose of venom used was to lethal doses by subcutaneous injection,
namely, 0.5 milligramme per kilo.
The following results were obtained.
Animal.
Weight,
E V. V.
in milligrammes
per kilo.
C. V. serum.
Result.
Rabbit 1 .
.
. 650 grammes .
0 . 5
4 c.c.
.
. Died in 4½ hours.
"
2
.
.
.
770
,,
.
0 . 5
10 „
.
.
„
2 0
„
,,
3
.
.
. 760
„
.
0.5
15 ,,
.
. Recovered.
" 4 (control)
. 610
„
.
0 . 5
Nil.
.
.
Died in 1 hour.
It would appear from these experiments that 15 c.c. of serum was able to
neutralise at least 0.5–0.035 = 0.4.65 milligramme. It can, therefore, be calcu--
l a t e d t h a t 1 c . c . wo u l d b e a b l e t o n e u t r a l i s e 0 . 0 3 1 mi l l i g r a mme .
TABLE VII.—Experiments to ascertain if H. C. V. serum has any neutralising
power for the venom of Enhydrina valakadien.
The test dose of venom used was 10 lethal doses by subcutaneous injection,
namely, 0.5 milligramme per kilo.
The following results were obtained.
Animal.
Weight.
E. V. V. in
milligrammes
per kilo.
H. C. V.
serum.
Result.
Rabbit 1
.
.
. 630 grammes .
0.5
4 c.c.
Died in 56 minutes.
„
2 (control) .
. 610
"
.
0.5
Nil
"
1 hour.
19
It is evident that this serum has no neutralising power for the venom of
Enhydrina valakadien.
TABLE VIII.—Experiment to ascertain if C. V. serum has any neutralising
effect on the clotting action of daboia venom in vivo.
The test dose of daboia venom used was about five lethal doses, namely,
0.5 milligramme, by intravenous injection. The following was the result.
Animal.
Weight.
D. V. in
milligrammes
per kilo.
C. V.
Serum
Result.
Rabbit
. .
. 880 grammes .
0.5
4 c.c.
Died in 9 minutes.
TABLE IX.—Experiments to ascertain if either C. V. serum or H. C. V. serum
has any neutralising effect on the action of daboia venom on the vaso-motor
centre.
A small non-lethal dose, namely, 0.02 milligramme of venom, was first
injected into the marginal vein of one ear. Half an hour after this injection a
mi x t u r e o f 1 mi l l i g r a mme o f v e n o m p e r k i l o . a n d 4 c . c . o f s e r u m wa s i n j e c t e d
into the marginal vein of the other ear. This mixture had been standing in
vitro at laboratory temperature for half an hour. The minimum amount of
daboia venom which can cause intravascular clotting in a rabbit by intravenous
injection is about 0.1 milligramme per kilo. Any quantity less than this amount
is non-lethal. We can take it then that the sera were now tested against not
more than ten lethal doses.
The following were the results obtained.
Anim al.
Weight.
Preliminary.
dose of D. V. in
milligrames
per kilo.
Test dose of
D. V. in milli-
grammmes per
kilo.
C. V.
serum.
H. C. V.
serum.
Result.
Rabbit 1
.
. 960 grammes.
0.02
1
4 c.c.
...
Died in 8 minutes.
" 2
.
•
9 7 0
,,
.
0.02
1
. . .
4 c.c.
,,
5
"
"
3 (control) . 970
„
.
0.02
1
Nil
Nil
"
6
3 3
A careful post-mortem examination made immediately after death in each
instance failed to reveal any intravascular clotting. The blood collected in a
test tube remained permanently unclotted.
D2
20
TABLE X.—Experiments to ascertain if either C. V. serum or H. C. V serum
has any neutralising effect on the clotting action in vivo of the venom of
Echis carinata.
The test dose of venom used was 0.1milligramme per kilo., namely, two
lethal doses, injected intravenously.
The following were the results.
Animal.
Weight.
.
E. C. V. in
milligrammes
per kilo.
C. V.
serum.
H. C. V.
serum.
Result.
Rabbit 1 .
.
. 1,220 grammes .
0 . 1
4 c.c.
. . .
Died in 11/2 minutes.
"
2 .
.
. 1,070 "
.
0 . 1
. . .
4 C.C.
" 11/2
"
„
3 (control) . 1,250
„
.
0 . 1
Nil.
Nil
,,
11/2 "
TABLE XI.—Experiments to ascertain if either C. V. serum or H. C. V. serum
has any neutralising effect on theaction of the venom of Echis carinata on
the vaso-motor centre.
A small non-lethal dose, namely, 0.002 milligramme of venom per kilo., was
first injected into the marginal vein of one ear. Half an hour after this injection
a mixture of 0.5 milligramme of venom per kilo. and 4 c.c. of serum was injected
into the marginal vein of the other ear. This mixture had been standing in vitro
at laboratory temperature for about half an hour. By previous experiments it
had been ascertained that the minimum amount of the venom of Echis carinata
which could cause intravascular clotting by intravenous injection into a rabbit
was 0.05 milligramme per kilo. Any quantity less than this amount was non-
lethal. We can, therefore, take it that the sera were now tested against not more
than ten lethal doses.
The following results were obtained.
Animal.
Weight.
Primary dose
of E. C. V. in
milligrammes
per kilo.
Test.dose of
E. C. V. in
milligrammes
per kilo.
C. V.
serum.
H. C. V.
serum.
Result.
Rabbit 1
.
. 900 grammes
0.002
0 . 5
4 c.c.
...
Died in 1 minute.
"
2
.
. 1,050
„
0.002
0.5
...
4 c.c.
„
2 minutes.
„
3 (control) .
980
„
0.002
0.5
Nil.
Nil.
„
1 m i n u t e .
A post-mortem examination made immediately after death in each instance
failed to reveal any trace of intravascular clotting. The blood collected in a test
tube remained permanently unclotted. .
2I
TABLE XII.—Experiments to ascertain if either C. V. serum or H. C. V.
serum has any neutralising power for the venom of Trimeresurus
gramineus.
The test dose used, namely, 2 milligrammes per kilo., was less than two
lethal doses.
The following were the results.
Animal.
Weight.
T. G. V. in
milligrammes
per kilo.
C. V. serum. H. C. V. serum.
Result.
Rabbit 1 .
.
. 8.40 grammes
.
2
3 c.c.
..
Died in 9 minutes.
" 2 .
.
. 85o
"
.
2
. . .
3 C.C..
" 6
"
" 3 (control)
. 810
"
.
2
Nil.
. Nil.
.
" 3
"
TABLE XIII.—Experiments to ascertain if either C. V. serum or H. C. V. serum
has any neutralising power for the venom of Crotalus adamanteus.
By previous experiments it was determined that the minimum lethal dose of
this venom by intravenous injection was 0'25 milligramme per kilo. of rabbit. This
a mount ki l l e d i n 4 1/ 2 da ys . The t e s t dos e now us e d wa s t wo l e t ha l dos e s , na me l y,
0.5 milligramme per kilo.
The following results were obtained.
Animal.
Weight.
C. A. V. in
milligrammes
per kilo.
C. V. serum. H. C. V. serum.
Result.
Rabbit I .
.
. 930 grammes .
0.5
4 c.c..
...
Died in 5 hours.
" 2 .
.
. 900
„
.
0.5
...
4 c.c .
.
" 6 "
" 3 (control)
. 900
0.5
Nil.
.
Nil.
.
"
8 "
TABLE XIV .—Experiments to ascertain if C. V. serum has any neutralising
effect on the hemolytic action of the venoms of various snakes.
The venoms used were those already mentioned. The following technique
was employed. Dog's blood was defibrinated : the red cells were washed three
times with 0.85 per cent. salt solution. A 5 per cent. suspension of the washed
red cells was made in 0.85 per cent. sterile salt solution. Of this suspension
1c.c. was the amount used in each preparation.
The test dose of venom was in each instance the smallest amount which could
bring about complete, or nearly complete, hæmolysis of this amount of red cell
suspension when a fixed quantity of serum complement was added. This test
dose and varying quantities of serum were mixed and allowed to stand in contact
for half an hour. To each tube there was then added I c.c. of the 5 per cent.
suspension of washed red cells and 0.5 c.c. of a two-fold dilution of dog's fresh
serum. The preparations were left in the incubator (35°C.) for one hour and
22
then placed in the ice chest for 18 to 20 hours. The following were the results
obtained.
The letters at the top of each column are the initial letters of the genus and
species of each snake (vide p. 2). The test dose of poison in each instance is
indicated at the top of each column.
C. V. serum.
N. T.
N. B.
B. C.
B. F.
H C
E. V.
V. R.
E. C.
T. G.
C. A.
0.025 mgr. 0.025 mgr. 0.025 mgr. 0.1 mgr 0.025 mgr. 0.1 mgr. 0.025 mgr. 0.1 m. 0.025 mgr. 0.025 mgr.
1 c.c.
...
Nearly
C H.
No H.
C. H.
C. H. Nearly
C. H.
C. H.
C. H.
C. H.
C. H.
0.8 „
...
Ditto
No H.
C. H.
C. H.
Ditto
C. H.
C. H.
C. H.
C. H.
0.6 "
. . . Ditto
No H. C. H.
C. H.
Ditto
C. H.
C. H.
C. H.
C. H.
0.4 „
...
Ditto
Trace
C. H.
C. H.
Ditto
C. H.
C. H.
C. H.
C H.
0.2 „
...
Ditto Marked C. H.
C. H.
Ditto
C. H.
C. H.
C. H.
C. H.
0.1 „
No H.
...
C. H.
...
...
. . .
. . .
. . .
. . .
. . .
0. 08 „
No H.
...
C. H.
...
. . .
...
. . .
. . .
....
. . .
0.06 „
No H.
...
C. H.
...
. . .
. . .
. . .
. . .
. . .
. . .
0.04 „
No H.
...
C. H.
...
..
. . .
...
. . . .
. . .
. . .
0.02 "
Mere
trace.
. . . C.H
. . .
...
. . .
...
. . .
. . .
. . .
0.01 "
C H.
...
C.H.
...
. . .
...
...
. . .
. . .
. . .
Nil (controL C. H. Nearly
C.H.
C. H.
C. H.
C. H. Nearly
C.H.
C. H.
C. H.
C H.
C. H.
C. H. = Complete hæmolysis.
TABLE XV .—Experiments to ascertain if H. C. V. serum has any neutralising
effect on the hœmolytic action of the venoms of various snakes
Exactly the same technique was employed as in the experiments detailed in
Table XIV. The following were the results obtained.
H.C.V. serum.i
N. T.
0.025 mgr.
N. B.
0.025 mgr.
B.C.
0.025 mgr.
B.F.
0.1 mgr.
H. C.
0.025 mgr.
E. V.
0.1 mgr.
V. R.
0.025 mgr.
E. C.
0.1 m
T. G.
0.025 mgr.
C. A.
0 . 0 0 2 5 m g r .
1 c . c . Mere
trace.
Marked C. H.
C. H. No H. No H.
C. H.
Mere
trace.
C. H.
C. H.
o.8 „
Ditto
Ditto
C. H.
C. H. Slight
No H.
C. H.
D i t t o . D i t t o . C. H.
C. H.
o.6 „
Trace Nearly
C.H.
C. H.
C. H. Nearly
C. H.
No H.
C. H. Trace
C. H.
C. H.
o.4 „
Slight
Ditto
C. H.
C. H.
C. H.
Trace
C. H.
Slight
C. H.
C. H.
0.2 „
Marked Ditto
C. H.
C. H.
C. H.
Slight
C. H. Nearly
C. H.
C. H.
C. H.
o.1 „
Nearly
C. H.
...
. . .
. . .
. . .
. . .
. . .
. . . ...
. . .
o.o8 „
C. H
. . .
.
. .
. . .
. . .
. . .
. . .
. . .
. . .
. . .
Nil (control) C. H.
Nearly
C.H.
C. H.
C. H.
C. H.
C. H.
C. H.
C. H.
C. H.
C. H.
C. H. = Complete hæmolysis.
23
TABLE XVI.—Experiments to ascertain if C. V. serum can neutralise the action
on citrate plasma in vitro either of cobra venom or of king cobra venom.
The technique employed was as follows : a fixed quantity, namely, one
milligramme, of each poison, was mixed in small test-tubes with different amounts
of serum. The mixtures were allowed to stand at laboratory temperature for half
an hour. There were then run into each tube 2 c.c. of citrate horse plasma
(1 per cent.). After these mixtures had stood for two hours, 0.4 c.c. of a 2
per cent. solution of calcium chloride was added to each tube. This amount
of lime solution clotted the control in about 25 minutes.
The results were noted at intervals as follows.
Citrate plasma 2 c.c.—Cacl2 (2%) :0.4 c c.
C. V. Serum.
Cobra Venom (1 milligramme.)
King cobra venom (1 milligramme.)
2 C.C.
.
.
.
......
Mere trace of clot after 20 hours.
1 . 8
"
.
.
.
. . . . . . Ditto.
1 . 6
"
.
.
.
. . . . . . Ditto.
1 . 4
"
.
.
......
No clot after 20 hours.
1.2 "
.
.
.
Clotted solid in 25 minutes
Ditto.
1
"
.
.
.
Ditto
Ditto
0 . 8
"
.
.
.
Ditto
. . . . . .
0 . 6
"
.
.
.
Clotted solid in 4o minutes
......
0 . 4
"
.
.
.
Found clotted after 20 hours
......
0.2 "
.
.
.
Trace of clot after 20 hours
......
0 . 1
"
.
.
.
No clot after 20 hours
......
0 . 0 8
"
.
.
.
Ditto
......
Nil (control)
.
.
Ditto
No clot after 20 hours.
The tube with lime alone clotted solid in 25 minutes.
From these experiments it is evident that 0.8 c.c. of C. V. serum completely,
and 0.6 c.c nearly, neutralised 1 milligramme of cobra venom : also, that 2 c.c. of
serum failed to neutralise the same amount of king cobra venom. There was,
-however, an attempt at neutralisation in the tubes containing the three greatest
quantities of serum.
TABLE VII.—Experiments to ascertain if C. V. serum can neutralise the
actions of the venoms of (1) Hoplocephalus curtus, (2) Echis carinata, (3)
Trimeresurus gramineus, and (4) Crotalus adanzanteus on citrate plasma
in vitro.
These four venoms rapidly clot citrate plasma in vitro without the addition
of any soluble salt of lime. The technique employed to test if C. V. serum had
any hindering effect on this action was as follows.
24
The test dose of each poison, namely, an amount which clotted the control
in a few minutes, was mixed with varying amounts of serum. The mixtures were
allowed to stand at laboratory temperature for half an hour. Then into each
tube there were run 2 c.c. of citrate plasma. A control tube without serum was
prepared in each instance.
The following results were obtained.
Amount of
Serum.
H. C. V.
( 0. 1 mi l l i gr . )
E . C . V .
( 0.05 milligr.)
T. G. V.
( 0.3 milligr.)
C . A . V .
( 0.05 milligr.)
1 C.C.
.
.
.
Clotted in
6 minutes.
Clotted in
5 minutes.
Clotted in
11 minutes
Clotted in
10 minutes.
0.5 "
.
.
.
Ditto.
Ditto
.
Ditto
.
D i t t o .
c . 1 "
.
.
.
Ditto.
Ditto
.
Ditto
.
D i t t o .
Nil (control)
.
.
Ditto.
Ditto
.
Ditto
.
D i t t o .
It is evident from these experiments that C. V. serum cannot prevent the.
clotting action in vitro of any of these four venoms.
TABLE XVIII .—Experiments to ascertain if H. C. V. serum can neutralise
the actions of the venoms of (z) Hoplocephalus curtus, (2) Echis carinata,
(3) Trimeresurus giamineus and (4) Crotalus adamanteus on citrate
plasma in vitro.
The same technique was used as was employed in the observations detailed
on Table XVII. The following were the results.
Amount of
s e r u m .
H. C. V.
(0.1 milligr.)
E . C . V.
(0.05 milligr.)
T. G. V.
(0.3 milligr.)
C . A. V.
(0.05 milligr.)
1 c.c.
.
.
. Liquid after 24
hours.
Clotted
in
5
m i n u t e s .
Clotted
in
13
m i n u t e s .
Clotted
in
1 1
m i n u t e s .
0 . 5
,,
.
.
.
Ditto
. .
Ditto
.
.
Ditto
. .
D i t t o .
0 . 1
,,
.
.
.
Ditto
. .
Ditto
. .
Ditto
.
.
D i t t o .
0 . 0 8 "
.
.
.
Ditto
. .
. . .
. . .
. . .
0 . 0 6„
.
.
.
Ditto
. .
. . .
. . .
. . .
0 . 0 4
„ .
.
.
. Trace of clot after
24 hours.
. . .
. . .
. . .
0.02 „
.
.
. Clotted after 24
hours.
. . .
. . .
. . .
0 . 1
„
.
.
. Clotted
in
13
minutes.
. . .
. . .
Nil (Control)
.
. Clotted
in
6
minutes.
Clotted
in
5
m i n u t e s .
Clotted
in
13
m i n u t e s .
Clotted in
11
m i n u t e s .