Medical 0fficers of the Army of India.
tion. Wall states that " cobra-poison cannot be said to produce a very great
effect on the circulation. The heart can be kept acting; and the blood circula-
ting for very many hours after the rest of the functions of the body have been
suspended, if only artificial respiration is continued. In ordinary cases of cobra-
poisoning the heart can generally be felt acting for a short time after respiration
has ceased."* But if this be so and death be due to asphyxia purely depend-
ent on diminution and cessation of respiratory movements, how does it happen
that death invariably ultimately occurs in spite of the continuous application of
artificial respiration ? The entire failure of artificial respiration to do more than
delay the occurrence of asphyxia is surely sufficient to suggest that the latter
cannot be purely dependent on failure of respiratory movements, and, when
taken along with the demonstrable effects of the venom on the respiratory pro-
perty of the blood, leaves little room to doubt that the fatal asphyxia which
normally occurs in cases in which artificial respiration is not applied is only par-
tially dependent on defective exposure of the blood to atmospheric oxygen. Under
normal circumstances such defective exposure does come into play to hasten
the fatal event, but, even where it is not present, as in cases where artificial res-
piration is applied, asphyxia occurs although after a longer interval. The phe-
nomena appear clearly to indicate that in the one case two factors productive of
asphyxia, defective respiratory property in the blood and defective exposure of
the latter to the air, are present, whilst, in the other, the former alone comes
into play. Artificial respiration apparently acts by giving the residual respira-
tory property of the blood an opportunity of securing the addition of fresh sup-
plies of oxygen from the air, but it in no way affects the progressive ferment-
action of the venom. The latter goes on steadily diminishing the respiratory
property of the blood until it falls below the limit which it must attain in order
to supply the respiratory demands of the system, and then death naturally
occurs in spite of the continued exposure of the fluid to atmospheric oxygen.
Another argument in favour of the belief in the presence of blood-change
as the primary result of the action of the venom and the essential cause of
the characteristic symptoms is afforded by the results attending treatment
by repeated injections of solutions of salts of strychnia. Were the primary
action of the venom, as is ordinarily supposed, one directly affecting the nervous
centres and giving rise to depression of their functional activity and conse-
quently to paralysis, it would be somewhat hard to explain why it is that treat-
ment with strychnia should have no appreciable effect whatever on the course
of the intoxication. But there can be absolutely no question that it has none,
and, more than this, that whilst this is the case—whilst the introduction into
the system of relatively large quantities of strychnia has no effect whatever
on the action of cobra-venom—the effects produced by the latter are to some
* O p , c
C 2