Medical Officers of
the Army of India.
13
or the evidence of any considerable solvent effect may be permanently absent,
because, in order to effect the occurrence of any readily appreciable solution, it
may be necessary that an amount of venom much in excess of that sufficient to
produce death should be present.
The data regarding the effects produced on coagulation show that when
a relatively very large proportion of venom comes into contact with a mass of
blood, coagulability is at once entirely abolished, and that smaller proportions,
although incapable of entirely preventing the occurrence of coagulation, delay
its onset, and affect the normal processes of contraction of the clot in degrees
varying in direct ratio with their amount. Here there is no even apparent con
-flict with the phenomena recorded as present in cases of death from cobra-
venom. In experiment XI, in which a relatively large quantity of dried venom
was directly introduced into the circulation, coagulation was excessively delayed
and extremely imperfect, and according to Richards the blood of the lower
animals normally remains permanently fluid "when a large quantity of cobra-
poison has been directly injected into the circulation, as, for example, into an
artery or vein."* But from the experiments it is also quite clear that the re
-spiratory properties of the blood may be profoundly affected by amounts of-venom
which are quite insufficient to prevent the occurrence of coagulation, and thus
that there are no good grounds for expecting that the blood after death from
cobra-bite should invariably be incoagulable, On the other hand, it is on record,
first, that the blood of animals generally is incoagulable where death has followed
the direct introduction of relatively large quantities of venom into the vascular
system ; and, second, that that of the human subject is normally incoagulable after
death from cobra-bite. The first of these two phenomena is clearly in complete
accord with the results obtained by causing cobra-venom to act on the blood
outside the body, and which demonstrate that large proportions of venom imme
-diately abolish both respiratory property and coagulability, whilst smaller pro
-portions give rise to excessive loss of respiratory property without apparently
proportionately affecting coagulability. From the data we should naturally be led
to assume that coagulability should, as a rule, be present after death from cobra-
bite, but absent where excessive quantities of the venom have come into play.
The fact that in cases of death from cobra-poison in the human subject the
blood should, as a rule, be incoagulable appears at first sight to be anomalous
as there are no good grounds for believing that a bite normally introduces a
larger amount of venom into the human body than it does into that of any of
the lower animals. There appears, however, to be a possible explanation of it ;
for, in very many instances at all events, life is more or less artificially prolonged
in the human subject after the injection of the venom into the system, by means
of various methods of treatment calculated to delay the onset of the comatose
*
Report of the Indian Commission f or the investigation of Snake-poisons, page 45.