sphere will hereafter be referred to. Haemorrhages from Australian
snake-poison are comparatively rare. Even at the bitten place there is
as a rule very little swelling and effusion and frequently none at all.
When it occurs it quickly disappears after strychnine injections. Only
a few cases have been reported as yet of blood-vomiting. In one of these
the haemorrhage took place soon after the bite and was so considerable
that it must have arisen from actual rupture of vessels consequent on
abdominal engorgement and not from mere diapedesis. It is very doubtful
whether the latter ever takes place here as it does after viper-bite in
India and elsewhere. Even the death-adder, although half a viper, and
producing more swelling and effusion locally than any other one of our
snakes, is not known to have ever produced the extensive effusions from
mucous surfaces in pericardium, lungs, &c., described above. More
research however is necessary, especially more carefully conducted
autopsies. Since Australia has taken the lead in this hitherto so
obscure department, every practitioner should make it his object and
special ambition to contribute his quota towards the elucidation of the
subject, not only by reporting successful cases, but also the
post-mortem appearances in unsuccessful ones, wherever it is
practicable. It is not by experiments on animals but by a hearty
co-operation of Australian practitioners that we can ever hope to
supplement our knowledge on this subject.
b.--The Respiratory Centre.
Paresis of this centre does not play as important a part here as it does
in India, more especially after cobra-bite. The peculiar, and as yet
unexplained, tendency of snake-poison to act with special virulence on
some centres, passing others by comparatively little disturbed, is
markedly shown by the cobra poison of India as compared with that of our
Australian cobra (_hoplocephalus curtus._) The unfortunate victims of
the former are tortured by an ever-increasing dyspnoca, and finally die
from asphyxia, under what are supposed to be carbonic acid convulsions.
They retain their consciousness more or less unclouded to the last, the
poison spending all its force on the respiratory centre, and leaving the
brain intact. Here we hardly ever see actual dyspnoca after the bite of
hoplocephalus or any other Australian snake. Respiration becomes quicker
at an early stage, and then, from hour to hour, shallower; but our
patients soon pass from sleep into coma, and suffer no respiratory
distress even when, in consequence of general paralysis, the respiratory
muscles cease to act, which usually takes place a few minutes before the
heart stands still.
Feoktistow records the following observations on cats with reference to
the respiratory centre:--Small intravenous injections of the fresh
poison (0.07-0.13 mllgr.) produced a great increase in frequency of
respirations (280-360 per minute). Section of both vagi at once reduced
this frequency, from which he infers that small doses act as an irritant
to the respiratory centre. When small doses were repeated several times,
the respiratory movements were gradually retarded, and asphyxia set in
through paralysis of the centre. Large doses produced this effect at
once, without any previous acceleration. Very large ones paralysed
respiration, heart, and vaso-motors almost simultaneously, and caused
the blood pressure to fall to 0. By the kymograph respirations were
found to become shallower in proportion to their frequency. As the
latter was reduced, they became at first deeper, but ere long shallower
again, and were occasionally interrupted by spasmodic inspirations.
Artificial respiration prolonged life for a short time only.
C.--Action on Centres of Cranial Nerves.
Among the symptoms denoting paresis of motor-centres of cranial nerves,
together with sympathetic ganglia, the first and most noteworthy is the
early dilatation of the pupil. This truly pathognomic condition is never
absent, and becomes intense when paresis becomes intensified into
paralysis. The most glaring light, in immediate proximity to the
eyeball, has then no effect whatever on the pupil. If it remains dilated
after strychnine injections have restored consciousness and the power to
walk, it is a sure sign that the snake-poison is not completely
counteracted, and will in all probability re-assert itself,
necessitating another injection, whilst a pupil restored to its normal
condition justifies the conclusion that the patient is safe.
Another symptom denoting paresis of the cranial nerve-centres is a
marked change in the expression of the face. The features become
relaxed, and lose their mimetic play. The cornea is dull, and, together
with the anterior surface of the eyeball, becomes dry, as the eyelids
are moved imperfectly, if at all, and the tears in consequence are not
properly distributed over the conjunctiva. The nostrils become more or
less immovable, and the naso-labial fold is obliterated, whilst the
lower lip hangs down. The lips are apart, as the lower jaw is not held
up by the muscles. When paralysis supervenes it drops entirely, and the
tongue protrudes.
Deglutition, somewhat difficult in paresis, is completely suspended in
the paralytic stage, through paralysis of the soft palate, the pharynx,
and oesophagus. Liquids forced on the patient in this extremity may
partly flow down the oesophagus, but will also enter the larynx, and
their administration should be carefully avoided.
D. Action on motor-centres of Cerebellum and Basal Ganglia.
Of this action little if anything is patent to observation. A certain
want of co-ordination in the movements has been noticed in the early
stage of paresis, and the peculiar staggering walk of persons in this
stage is probably owing to an affection of the motor-centres of the
cerebellum. That they do not escape the action of the subtle poison,
when symptoms denoting the invasion of all the other motor-centres
throughout the body are in evidence, we have every reason to assume.
The co-ordination and automatic regulation of the lower motor-centres
must necessarily escape observation when the function of these centres
is partially suspended, and when, moreover, the powerful currents of
nerve force the cerebellum and basal ganglia receive from the motor
cortical centres of the cerebrum are partially if not wholly withdrawn.
E. Action of the Motor Cortical Centres of the Cerebrum.
In all but the very lightest cases of snakebite-poisoning there are
always symptoms manifested that cannot be referred to any other cause
than an invasion of the centres now under consideration. They range from
mere stupor, confusion of thought and delirium to the deepest coma, with
complete extinction of consciousness and insensibility to all external
impressions. Coma is a frequent and in serious cases an almost
invariable symptom in Australia. After the bite of our death adder only
we find persons sometimes collapse and expire suddenly, when still
conscious and able to answer questions rationally. Coma invariably
develops from sleep. It is, in fact, sleep intensified. An almost
irresistible desire to sleep is one of the first symptoms to be
observed. If the dose of poison imparted by the snake has been small,
the desire may pass off or the sleep may not assume the form of coma,
but in all serious cases it quickly assumes that form. _Vice versa_ the
deepest coma becomes sleep again, when the suspended function of the
cortical centres is roused by strychnine injections. The insensible and
completely paralysed patient usually announces the gradual return of
consciousness by a few groans and uneasy movements and not unfrequently
begins to snore, as in ordinary sleep, when a smart shake at the
shoulder will rouse him into full consciousness. At other times this
transition from coma back to sleep does not take place and consciousness
returns quite suddenly, the persons opening their eyes and looking
around them, dazed and bewildered, but perfectly conscious at once. When
coma is fully established and the largest and most powerful
motor-centres have succumbed to the insidious poison, general paresis
becomes general paralysis and all the motor-centres of the body are in a
condition of more or less suspended functional activity. This and this
only is the condition of the centres, the whole secret of snake-poison,
that has puzzled the human mind for ages and yet appears so simple when
discovered at last. It is beautifully and strikingly illustrated in the
phenomena before us. We have coma and complete general paralysis, every
motor-nerve cell, from the highest psycho-motor one downwards, is thrown
into a state of torpor and has ceased to discharge the life force that
regulates every process of life and the entire absence of which
inevitably must be death. Only weak, lingering currents are sent forth
yet and put off the inevitable finale for a time. But the strychnine is
injected and mark the change. It courses quickly to every one of the
sleepers, for whom it also has an affinity, but the direct opposite to
that of the deadly venom that has overpowered them. It touches them as
if with the wand of a magician and orders them to awake and do their
work. There is no disobeying the mandate, for it is founded on one of
nature's unchangeable laws. Almost immediately the cells begin their
work again, the life streams flow afresh, coma and paralysis vanish and
within a very short time the subject of this beautiful experiment is
snatched from the brink of the grave and restored to life and health.
The phenomena of sleep and coma as the result of a poison acting as a
depressant of motor nerve force afford food for some interesting
speculations, which, however, as more concerning the psychologist, the
writer can only glance at here. It is evident that in the highest of
psycho-motor centres, the organs of thought and of consciousness, the
paresis of the lower centres assumes the form of sleep, and paralysis
that of coma. Sleep, as a partial, and coma, as a complete, obliteration
of thought and consciousness must, therefore, be intimately connected
with motor nerve function, sleep being a reduction, coma a suppression
of the function, or a suspension of thought. Ideation, to use J. S.
Mill's very appropriate term for the thought process, appears to be
effected by motor nerve currents or, at all events, to be accompanied by
them and suspended with their suspension. The thinking principle, the
nous within us, is no doubt more than mere nerve action, but it can,
apparently, not manifest its presence without motor nerve cells in
healthy action. Every thought, though not synonymous, is evidently
synchronous with a current of motor nerve force, and it is not
improbable that, by means of these currents, that silent transference of
thought is effected from brain to brain, which modern psychology has
demonstrated to be not only possible but actual under certain
conditions. But further speculation on these interesting mysteries it
would be out of place here to indulge in.
F. Action on Sensory Centres and the Reflexes.
The sensory sphere remains comparatively unaffected in mild cases, and
in the early stages of more serious ones, but when paresis has deepened
into paralysis, sensation becomes ever more blunted, and with the advent
of coma, of course, quite extinct. Reflexes, both superficial and deep
ones, are also completely abolished at this period of the poisoning
process, and the nerves of special sense do not react against any, even
the strongest possible stimulation. The eye stares vacantly into a
glaring light held close before it, and the widely dilated pupil shows
no sign of reaction. The ear also appears deaf to any noise, and strong
ammonia vapour is inhaled through the nose like the purest air, whilst
pricking, beating, and even burning the skin elicit not a quiver of a
muscle.
Feoktistow's experiments with regard to reflexes, more especially their
restoration by strychnine, differ in their results entirely from
Australian observations. Whilst we have no difficulty in restoring them
with the drug on man as well as the domestic animals, his experiments on
frogs were a failure, and merely showed a decided antagonism between the
two poisons. He did not succeed in restoring the reflexes, and, instead
of following up with experiments on the higher animals, he trusted
implicitly to his results on frogs, and thus lost his opportunity.
G. Irregularities in the Action of Snake-poison.
There is in the whole range of toxicology not a single condition known
to us in which the symptoms, both in chronological order and in their
strength and relation to each other, show as much variety as those of
snake-poison. Experienced observers will agree with the writer that it
is but rarely we find two cases of snakebite exactly alike in the
symptoms they present. Some of these puzzling variations have already
been alluded to, but it is necessary to consider them a little more in
detail. Apart from quantitative differences in the poison imparted, they
arise principally from the strange capriciousness with which the poison
concentrates its action on special nerve centres and leaves others
comparatively intact.
The nearest approach to regularity and orderly sequence of the symptoms,
as described in the foregoing pages, we find in Australia after the bite
of the tiger snake (_Hoplocephalus curtus_) and the brown snake
(_Diemenia superciliosa_), more especially that of Queensland. Here we
can trace the action of the poison distinctly from centre to centre,
from the lowest part of the anterior cornua up to the cortex cerebri,
and even throughout the sympathetic ganglia as far as they are patent to
observation. The poison of these snakes is extremely diffusible and
quickly absorbed. It spreads with rapidity and nearly equal force over
all the motor centres, the symptoms following each other so quickly as
almost to appear simultaneous, though, in reality, successive. But even
the poison of these snakes leaves the arms only slightly paretic, when
paralysis in all the other voluntary muscles is well pronounced, and
does not paralyse them until coma has set in. It also touches the
respiratory centre but slightly. Sometimes coma is light and the
patients can be roused for a little while, at other times it is deep and
lasts till death. But even greater variations are observed occasionally.
In one very extraordinary case of tiger snakebite, the patient, a child
of 9 years, remained conscious to the last, and after vomiting blood
freely died under symptoms of heart failure. In rare cases the symptoms
resemble those of cobra poison.
If we turn from these to the black snake (_Pseudechis porphyriacus_) a
different picture presents itself. Its poison does not produce so deep a
coma and often none at all. The patients generally feel drowsy and fall
asleep, but are easily roused and sometimes awake spontaneously. There
is also not the same amount of muscular paralysis. They are frequently
able to walk a few steps with assistance and can move in bed, the arms
especially being almost free from paresis. But the insidious poison none
the less does its work, though its effects are less patent. It
concentrates its action on the vaso-motor centre. The victims from hour
to hour become more anaemic in appearance through increasing engorgement
of the abdominal veins. Anaemia of the nerve-centres hastens the
collapse, and from the combined effects of this and heart failure death
takes place suddenly and quickly as if in a fainting fit. Here then we
have an approach to the effects of viper poison which is also shown in
the greater amount of swelling and effusion around the bite and in the
bitten limb.
This approach is still closer in the poison of the death adder
(_Acantophis antarctica_). There is generally much extravasation of
blood locally. Muscular paralysis is also less pronounced, but sudden
collapse from vaso-motor paralysis not unfrequently takes place, when
the patients fully conscious are still able to sit up. That leading
feature of viper poison, diapedesis with haemorrhage, does not occur with
either.
If we turn from Australian to Indian snakes, the peculiar tendency of
the poison to concentrate its action on special nerve-centres becomes
still more marked. The predilection of the cobra poison for the
respiratory centre has already been dwelt on. More remarkable and
strange is the action of the Indian viper-poison on the minute ganglia
in the vaso-motor nerve ends, which control the capillary circulation,
and by their paralysis bring about extensive haemorrhage through
diapedesis.
It is quite impossible for us with our present scanty knowledge to
account for these peculiarities and irregularities in the action of a
poison, which we know now to accomplish its destruction of animal life
by one uniform design and principle of action. That the protean forms
under which the poison-symptoms present themselves are one and all the
result of reduction and suspension of motor nerve currents may now be
accepted as a well proven and fully established scientific fact. But why
the effects of one and the same cause are so varying in their
appearance, why the poison of different varieties of snakes, and even
that of the same variety under different circumstances, make such a
capricious selection among the various motor nerve-centres we can not
explain and probably never will. Chemical analysis of the dead poison,
no matter how minutely and elaborately it may be effected, will probably
never throw much light on the "why" of this strange puzzle, for the
subtle phenomena of life are apt to elude the grasp of the analyst. We
have to do with a poison transferred from one living organism into
another one and modified in its action by the condition of the giver and
the constitution and peculiarities of the recipient quite as much
probably as by slight variations in its chemical composition. Accepting
the "why" of these phenomena like that of many other ones, simply as a
fact not to be accounted for at present, we must be content to know
"how" they are effected, and, what is of more immediate and paramount
importance to know, that we now have an antidote that will deal
successfully with them all, that the convulsions and haemorrhages of the
Indian viper-poison and the asphyxia of that of the cobra will yield as
readily to strychnine, when properly and boldly applied, as the coma and
general paralysis following the bite of the deadly tiger snake.
[Illustration]
THE ANTIDOTE.
The theory of the action of snake-poison as that of a specific
nerve-poison, depressing and more or less suspending the function of the
motor nerve-centres throughout the body, has in the foregoing pages
received a double proof of its correctness.
In the first place, all the symptoms the snake-poison produces have been
passed in review, and shown to be fully explainable by this theory. On
this ground alone it may be claimed to have been fully established; for
it is an axiom in science that a theory on any subject must be accepted
as correct, if it accounts satisfactorily for all the phenomena
observable in connection with that subject by showing them to result
from the operation of one law. The second inductive proof of the
correctness of the writer's theory has been rendered by the experiments
of Feoktistow on animals.
Science, however, demands that a theory thus established inductively
must also stand the test of practical application or deduction. It says
in the present case:--"Granting your theory to be correct, it is but a
theory, which, however valuable it may be as a contribution to science,
is of little value to mankind if you cannot apply it practically. If
snake-poison merely acts as a depressant on motor nerve-cells without
interfering with their structure, you must be able to counteract it by
administering some drug or substance which acts as a powerful stimulant
on these cells, if such a substance can be found."
It is another illustration of that wise adaptation of means to ends
which, throughout the domain of nature, denotes the presence and rule of
a Supreme Intelligence, that this substance has been provided for us by
nature, though we have been long in finding it. Its discovery in
strychnine, and its successful application as the long and vainly sought
antidote to snake-poison, are glorious triumphs of scientific deduction.
Strychnine is the exact antithesis to snake-poison in its action. Under
its influence every motor nerve-cell throughout the system sends forth
stronger currents of nerve force than it does in its normal state. These
currents run alike from cell to cell, and from cell to peripheral fibre,
and act by means of the latter on all contractile, and especially all
muscular tissue, causing contractions, which, after poisonous doses of
the drug, assume the form of tetanic convulsions, provoked by the
slightest touch or even noise in consequence of highly intensified
reflex action.
Whilst, then, snake-poison, as we have seen, turns off the
motor-batteries and reduces the volume and force of motor-nerve
currents, strychnine, when following it as an antidote, turns them on
again, acting with the unerring certainty of a chemical test, _if
administered in sufficient quantity_. Purely physiological in its
action, it neutralises the effects of the snake-poison, and announces,
by unmistakable symptoms, when it has accomplished this task, and would,
if continued, become a poison itself. Previous to this announcement its
poisonous action is completely neutralised by the snake-poison, and the
latter would therefore be equally as efficacious in strychnine-poisoning
as strychnine is in snake-poisoning. Strychnine, in short, is the
antidote _par excellence_ of snake-poison, and cannot be surpassed by
any other substance known to us.
With the symptoms following the introduction of the subtle ophidian
virus into the human and animal system so markedly pointing to
strychnine as the antidote, it appears a matter of surprise that it was
not used as such before and that it was left to the writer to discover
the antagonism between the two poisons. Misleading experiments with the
drug on animals erroneously considered to be final in their results,
together with confused and contradictory notions about the action of
snake-poison, were the chief factors, already pointed out, that caused
research on this important subject to remain for centuries so barren of
results, and made even able investigators with more correct views than
the rest, postpone the discovery of a physiological antidote to a more
advanced state of science, when all the time it was lying ready at their
hands.