# Indian Snake Poisons, Their Nature and Effects/Chapter I

CHAPTER I.
THE PHYSIOLOGICAL EFFECTS OF THE POISON OF THE COBRA (NAJA TRIPUDIANS).
The inquiry that naturally presents itself first in considering the subject of snake-poisoning is:—How does snake-poison kill? and what are the changes it effects in the animal system? And as a consequence of this:—Is there only one poison common to all snakes, or are there several? Upon the answers to these questions depend both the certain recognition of snake-poisoning when it comes under observation, and the indications that must serve as guides to us in the treatment of it.
To answer these questions, it will be necessary to examine, with great care, the symptoms produced by ​various poisonous snakes, in order to detect any differences in their effects, paying special attention to those conditions on which the fatal results are dependent, and any prominent signs that will enahle us, with certainty, to say if, in a given case, we have really to deal with the results of snake-bite, or not.
As the cobra (Naja Tripudians) is at the same time the commonest and the most deadly of all Indian poisonous snakes, it will be best first to consider the symptoms produced by it, and the ways in which its poison may be fatal. To do this it will be necessary to detail a sufficient number of experiments to bring into prominence all the characteristic symptoms of cobra poisoning, and from them to deduce the direct causes of death. We shall then have a standard by which we shall be able to contrast the effects of the poisons of the other species of venomous snakes.
To begin with the symptoms as they occur in human beings; the following is an account, by Dr. Hilson, of a case that came under his own observation : —
"On a night in June, at about half-past 12 o'clock, Dabee, a Hindu punkah coolie, was bitten on the shoulder by a cobra, whilst sleeping. On inspecting the wound, there were found over the prominence of the right deltoid muscle, and about three quarters of an inch apart, two large drops of a clear serous-like fluid tinged with blood, which had apparently oozed from two small punctures, so minute that they could not be ​perceived by the naked eye. A burning pain was complained of in the neighbourhood of the bite, which rapidly increased in intensity, and extended so as to affect a circular portion of the integument of the size of mn ordinary saucer; and, judging from the description given of it, it was very similar in character to that produced by the sting of a scorpion.
"At 12.45 A.M., or about a quarter of an hour after being bitten, he complained of a pain in his shoulder shooting towards his throat and chest, and said he was beginning to feel intoxicated ; but there was nothing in his appearance at this time to indicate that he was in any way under the influence of the poison. On the contrary, he was quite calm and collected, and answered all questions intelligently, at the same time that he was fully alive to the danger of his condition. The pupils were not dilated, and they contracted when exposed to the light of a candle ; his pulse was normal, and there was no embarrassment of the respiration. About five minutes after, he began to lose control over the muscles of his legs, and staggered when left unsupported. At about 1 o'clock, the paralysis of the legs having increased, the lower jaw began to fall, and frothy and viscid saliva to ooze from the mouth. He also spoke indistinctly, like a man under the influence of liquor. At 1.10 A.M. he began to moan, and shake his head frequently from side to side. The pulse was now somewhat accelerated, but was beating regularly. The ​respirations were also increased in frequency. He was unable to answer questions, but appeared to be quite conscious. His arms did not seem to be paralysed. At 1.15 A.M., twenty-five minims of liquor ammoniae were rapidly injected under the skin of the fore-arm ; but as this produced no results, the basilic vein was laid bare, and twenty-five minims injected into it.
"The operation caused no amelioration in the symptoms, and the condition was evidently becoming critical. He continued to moan and shake his head from side to side, as if trying to get rid of viscid mucus in his throat. The respirations were laboured, but not stertorous. The external jugular vein of the left side was next exposed, and twenty-five minims of the liquor amraonise injected into it; but without producing any good eflfect. The breathing gradually became slower, and finally ceased at 1.44 A.M., while the heart continued to beat for about one minute longer. No convulsions preceded death, which took place in one hour and five minutes after the infliction of the bite."
From the description given of the snake, there can be no doubt that it was a cobra, and it is clear that the remedy administered had no more effect on the symptoms than it had on the result. It is a good description by a careful observer, and may be taken as a typical example of cobra-poisouing in the human subject.
On the lower animals, from which alone we can learn the details of the poisoning process, and the exact ​causes on which the fatal results depend, the effects of cobra-poisoning are well seen in the following cases.
Experiment I.
A medium-sized pariah dog had 0.6 cubic centimètre (about 10 minims) of fresh cobra-poison injected subcutaneously.
5.21 P.M. Injection.
5.23 P.M. Lame in the leg in which the injection was made.
5.29 P.M. Lies down, but does not seem affected.
5.35 P.M. Somewhat sleepy.
5.45 p.m. Got up of its own accord; salivation; retching.
5.47 P.M. Staggers about, and hangs down its head.
5.48 P.M. Cannot stand.
5.49 P.M. Sleepy; respirations 40 per minute.
5.52 P.M. Pulse 72.
5.55 P.M. Convulsions.
5.56 to 5.59 P.M. Convulsions.
6.5 P.M. Eespirations quite ceased; heart beats 84 per minute; pupils commencing to dilate.
6.7½ P.M. Heart stopped. Dead.
Experiment II.
At 10.46 A.M. a pariah dog was bitten in the thigh by a cobra.
11.14 A.M. Very lame in the bitten limb.
11.27 A.M. Affected by the poison; staggers when it attempts to walk; chewing movement of jaw and lips.
11.28 A.M. Salivation.
11.30 A.M. Pupils somewhat small.
11.31 A.M. Attempting to vomit.
11.35 A.M. Respiration becoming slower.
11.37 A.M. Respirations 16 per minute.
11.38 A.M. Copious salivation.
11.39 A.M. Respirations fallen to 12.
11.40 A.M. Respirations of a jerky character.
11.42 A.M. Tongue hanging out of the mouth.
11.43 to 11.45 A.M. Convulsions.
11.46 A.M. Convulsions lessening.
11.47 A.M. Convulsions stopped.
11.47½ A.M. Respiration completely stopped ; pupils dilating.
11.49 A.M. Heart stopped. Dead.
Experiment III.
A pariah dog was watched for about an hour, during which his respirations varied from 40 to 62 a minute.
His pulse was 120.
At 11.56 A.M. a very small quantity of fresh cobra virus was injected subcutaneously into the left thigh; the amount injected was about 0.l cubic centimetre. The dog lay down after the injection, and seemed to take no notice of what had been done.
12.14 P.M. Pulse 108.
12.15 P.M. Respirations 48,
12.26 P.M. Eespirations 44, occasionally a deep respiration; dozing.
12.29 P.M. Eespirations 36.
12.32 p.m. Respirations 28; very regular; asleep.
12.35 P.M. Respirations 24; respiratory movement very slight; still sleeping.
12.37 P.M. Respirations 24.
12.40 P.M. Respirations 22.
12.43 P.M. Awoke suddenly with a start, probably aroused by flies ; chewing movement of lips and jaws.
12.45 P.M. Attempting unsuccessfully to rise; staggered about on his fore-legs.
12.47 P.M. Respirations 26; hardly perceptible, of a somewhat spasmodic character, and lasting an exceedingly short time; salivation.
12.49 P.M. Pupils about normal.
12.50 P.M. Convulsive twitchings of the whole body.
12.52 P.M. Tongue hanging out; convulsions much stronger.
12.55 P.M. No trace of normal respiratory movement, only convulsions : micturition.
12.56 P.M. Pupils slightly contracted.
12.58 P.M. Convulsions are becoming feebler.
12.59 P.M. No convulsive or respiratory movement whatever; pulse 120.
1.1 P.M. Pulse 96; pupils dilating. The only sign of life remaining is the heating of the heart.
1.2 P.M. Pupils fully dilated; heart stopped. Dead.
Experiment IV.
A pariah dog was bitten by a vigorous cobra. The skin in the niiddle of the dog's back, as near as possible at an equal distance from his fore and hind legs, was taken up, and the cobra injected its poison into it.
8.25 A.M. Infliction of the bite.
8.26 A.M. The dog is evidently in some pain from the bite ; he turns round and round in endeavouring to
lick the bitten part.
8.29 A.M. Is quieter; pupils normal; no symptom.
8.30 A.M. Able to walk and stand perfectly well.
8.31 A.M. Pupils normal, neither contracted nor dilated : they answer weil to light.
8.35 A.M. Slight spasm of diaphragm.
8.36 A.M. Can walk perfectly.
8.39 A.M. Walks with uncertain tread, as if weak; all the legs equally affected.
8.40 A.M. Staggering, but no difi"erence can be observed between the fore and hind legs.
8.41 A.M. Fell over, his fore-legs first giving way; pupils about normal — at any rate, no tendency to dilatation.
8.42 A.M. Lying on his side unable to rise, or even to stand when placed on his legs ; all his legs equally
weak; twitching of respiratory muscles, also to a less extent of certain muscles in his limbs.
8.43 A.M. Tongue protruded.
8.44 A.M. Pupils contracted; all motion ceased except that of heart.
8.46 A M. Slight spasm of depressors of larynx.
8.46 A.M. Heart alone acting; pupils suddenly dilated widely.
8.47 A.M. Heart stopped. Dead.
Experiment V.
A large cock had two milligrammes (about ·03 grain) of dried cobra-poison, dissolved in one cubic centimetre of distilled water, injected into its leg.
3.13 P.M. Injecticn.
3.20 P.M. Respirations 30 per minute.
3.34 P.M. Prefers to sit, but can stand and walk.
3.38 P.M. Head drooping, as if the neck were too weak to support it, but from time to time the head is raised with a jerk.
3.39 P.M. Beak rests on ground.
3.41 P.M. Respirations 25; can barely stand.
3.48 P.M. Respiratory movement very slight.
3.50 P.M. Cannot stand.
3.54 P.M. Cannot keep the eyes open.
3.55 P.M. Respirations 19; pupils somewhat contreated.
4.3 P.M. Respirations 16; of a somewhat exaggerated character.
4.5 P.M. Comb has become of a dusky purple colour; slight couvulsive movements of body.
4.9 P.M. Respirations 9.
4.13 P.M. Slight convulsions.
4.15 P.M. Pupils contracted ; answer to light.
4.17 P.M. Convulsions.
4.20 to 4.22 P.M. Convulsions continuing, but gradually becoming less violent.
4.25 P.M. Pupils widely dilated. Dead.
Experiment VI.
A medium-sized frog (Rana tigrina) had a solution of five centigrammes (.77 grain) of dried cobra poison, in one cubic centimetre of distilled water, injected into its dorsal sac.
12.42 P.M. Injection.
1 P.M. No change.
1.23 P.M. Struggling violently to escape.
1.40 P.M. Becoming paralysed.
1.58 P.M. Dead.
Prom these cases it may be gathered that the symptoms of cobra-poisoning are as follow: —
The first manifestation of cobra-poison having been injected beneath the skin is a sensation of pain in the bitten part. It seems to vary much in degree, but is ​usually described, as in the case given, as being of a stinging and burning character. The site of the wound may also become swollen, red, and painful on pressure. The evidence of the pain occurring in dogs is very clear: the animal often turns round and licks the bitten spot; and if it is the leg that is wounded, it either limps on that leg, or, what is more usiial, it draws it up, so as to raise it and relieve it completely of the weight of the body. This action has been termed paralysis of the bitten leg, due to the local contact of the poison with the muscles. Now, though it can be proved that the local effect of cobra-poison on muscle is to weaken it, yet after the bite of a cobra a very small extent of muscle indeed comes in contact with the poison, very often none at all ; and if the limb were really paralysed, it would hang uselessly down, dragging upon the ground, instead of being drawn up.
An interval now occurs before the accession of any fresh symptom, but its length varies greatly in different cases. In that of the man quoted it was fifteen minutes; but this is probably considerably under the average time. In another case, related by the same careful observer, an hour and a quarter elapsed in this way; and an intelligent eye-witness, who described a case with great accuracy as to details, stated four hours was passed before any change was noticed. Taking into consideration all the evidence on the subject, it appears probable that in the majority of cases of cobra-bite in ​the human subject, an interval of an hour occurs before any constitutional symptoms are developed. Under certain exceptional circumstances the symptoms of poisoning may begin almost at once. In the case of dogs bitten by cobras this interval varies very greatly — perhaps fifteen minutes may be taken as its average length, or perhaps a little less.
The retardation of the constitutional symptoms probably means that before cobra-poison can produce any, effect, it must be present in the blood in certain proportion, and, of course, in slow absorption, either due to the small quantity of the poison injected, or to its being injected into an unfavourable situation, some time must elapse before this proportion can be attained. In these cases the symptoms are delayed, as is also the fatal result ; whereas, should the poison enter the circulation rapidly, as by injection into a vein, the symptoms and fatal result follow immediately. At the same time it is clear that for a short time a fatal quantity of poison may be present in the circulation without producing a symptom ; for the bitten part may be sometimes amputated before the occurrence of any sign of poisoning, yet, nevertheless, the animal may die.
In man the first constitutional symptom that cobra poison produces seems to be a feeling of intoxication, although there appears to be no outward evidence of it. That this symptom is not more frequently described ​in the history of cases can be easily accounted for by the fact that it would require a certain amount of intelligence on the victim's part to mention it; and in animals, of course, it is impossible to get proof of a purely subjective condition.
The special symptoms of cobra-poison now rapidly manifest themselves. It man it is very commonly observed that the patient cannot any longer keep his eyes open, and about this time it is found that he is losing power in his legs. When he walks he staggers, and, if left unsupported, falls. The arms seem to retain their strength much longer. In the case of dogs, the animal at this stage can scarcely stand without falling frequently, but there does not seem to be that difference between the anterior and posterior extremities that is observed in the legs and arms of a man. Usually, a dog loses strength equally on his fore and hind legs, and rolls from side to side helplessly.
The order in which the symptoms now occur varies in different individuals. In some, loss of the power of speech and of raising the lower jaw is shown, and afterwards profuse salivation; but the salivation may precede. But whichever may occur first, the tongue and the larynx become speedily paralysed ; the patient is unable to speak or to clear his throat or to swallow ; and the saliva, which is profusely poured forth, trickles down the lips, the patient being no longer able to eject it voluntarily. In dogs it is not unusual for the ​salivation to be manifested before any other constitutional symptom, and in them a chewing movement of the jaw and lips is often seen immediately before the salivation. Nausea, retching, and vomiting are of frequent occurrence both in men and dogs.
The paralysis now becomes more general and decided. The patient lies on his back, almost incapable of movement. He threatens to be suffocated by the saliva running into his paralysed larynx; should, however, the head be placed on one side, the abundant secretion will flow down his lips. His limbs at this time may be subject to starlings and muscular twitchings. His breathing becomes slower and slower, and the respiratory excursus is lessened. He appears to be conscious, but is unable to express himself, through the paralysis of his larynx and tongue ; but it is not unfrequently the case for the victim to become quite unconscious. The action of the heart is somewhat quickened, but the organ acts with fair strength. At length the breathing, too slow and too slight to support life, ceases, and with or without general convulsions the heart shortly after stops.
In dogs, as might be expected, convulsions are much more common than in man, being very generally present; and while in man the extinction of the respiratory act is, as a rule, a very slow and gradual process, in dogs it is not unusual for respiration to stop quite suddenly, and almost immediately after for its place to be taken by violent convulsions. ​In birds the symptoms are usually very regular in their occurrence. There is the same appearance of local pain. The bird then generally seems drowsy, from its being unable to keep the eyes open, the head droops as if the neck were unable to support it, but the bird constantly recovers itself with a jerk. It at last sinks down to the ground, ultimately falling over on its side, unable to raise either its head or itself. The pupils are, as a rule, somewhat contracted, the eye often watering. The respirations finally become exceedingly slow, and then cease, convulsions and death following. It sometimes happens, as in mammals, that the respiratory centre is almost simultaneously stimulated and paralysed, the bird dying at once.
In the amphibia, there can scarcely be said to be any symptoms of cobra-poisoning; the frog, for instance, only becomes more and more sluggish and paralysed, and is at last found to be dead.
It will be necessary to consider some of the more important conditions in detail, after having noticed the appearances to be found after death.
Post-Mortem Appearances in Cases of Death by Cobra-bite.
Rigor mortis generally comeson about the usual time and is as well marked as it is in death from ordinary causes. The blood in man is fluid, as a rule, and in the ​lower animals coagulated. If examined directly after death no changes can be recognised by the microscope. After a time the corpuscles may change in shape, become crenated, and blood-crystals may form, but at the moment of death no change can be recognised. The parotid glands may be swollen. The brain presents no marked deviation from normal. The veins of the pia mater are usually gorged with blood, and the ventricles often contain turbid fluid. The muscles are often of a dirty red colour. The subcutaneous veins bleed freely on section. The lungs may be pale and contain but little blood, but in the human subject they are generally found congested, the bronchi and the smaller tubes being often filled with a thin frothy fluid, and their lining membrane intensely injected. Occasionally portions of food or of remedies are to be found in the air-tubes, the result of administration while the larynx was paralysed. The heart is distended with blood, especially the right side. The liver bleeds freely on incision, and is quite dark from contained blood, but this is not universal. The kidneys vary from normal to excessive congestion, being seen in all stages. The stomach may, or may not, contain food — a proof that cobra-poisoning in the human subject does not always cause evacuation of the contents of the stomach. There is no regular change in the intestinal tract, which may be injected in places. The bladder is generally firmly contracted.
Local Effects of Cobra-poison.
It has been mentioned that severe pain is generally felt in the region of the cobra-bite. There are, however, gases on record which seem to prove that the intense mental shock of snake-bite renders the victim occasionally, insensible to the pain. This pain is accompanied by, or rather is dependent upon, a very characteristic local condition, which is of the utmost practical importance. If the body of a man or animal killed by snake-bite be examined, there may be scarcely a sign on the skin to mark the spot where the snake inflicted its bite; or possibly one or two small punctures, or even a scratch, may be found, especially if the part bitten be the fingers, which, of course, are apt to be forcibly and involuntarily retracted when the bite is felt. It may even happen that the part is slightly swollen or discoloured. But whatever may be the condition of the external aspect, there will be found a distinct change in the state of the parts beneath. If an incision be made through the skin and carried through the punctures made by the snake's fangs, very little difference will be found in the true skin. It may be a little more injected than normal, and the punctures will be found to be intensely so just at the edges, and a small quantity of blood may be effused there. But the areolar tissue lying beneath the true skin is the site of the chief change. It will generally be seen to be of a purple colour, and to be infiltrated with ​a large quantity of coagulable purple blood-like fluid. In addition to this effusion the whole of the neighbouring vessels are intensely injected, which injection gradually fades as the site of the poisoned part is receded from, so that a bright scarlet ring surrounds the purple area, and this in its turn gradually fades into the normal colour of the neighbouring tissue. At the margin, also, the purple blood-like effusion is replaced by a pinkish effusion, which wells out as the incision is made. This effusion of pinkish fluid may often be traced up in the tissues surrounding the vessels which conveyed to the system the poison they had absorbed from the part. In one case, in which the victim was bitten on the hand, the effusion from the veins could be traced as high as the elbow. These are the essential characters of the local effects produced by cobra-bite; but they may vary a good deal in degree, depending, probably, upon the amount of poison injected and the time the subject lived after being bitten. It has been asserted that the nature of these local changes in snake-bite is merely a hsemorrhage into the tissues from vessels that have been divided by the fangs of the snake, with effusion of blood from the vessels around. But though it is true that sometimes a very small amount of blood may be found at the site of the punctures, yet it is clear that this explanation will not account either for the great pain that is felt in the part, or for the intense injection of the neighbouring vessels. To determine the ​nature of these changes, dissections were made both on the human subject and on the lower animals of individuals that had died of snake-bite ; also incisions were made into the tissues at the place where snakes had bitten at various intervals after the bite. The result of these observations is to show that directly after the poison is injected into the tissue its vessels become enlarged and gorged with blood, effusion is poured out immediately; and as the engorgement and stngnntion of blood increase the effusion becomes more blood-like, from its containing more of the contents of the vessels. Now, these processes are singularly rapid in occurring. In an animal that only lived thirty seconds after the injection of the poison, a well-marked circle of vascular injection was found at the site of the poison. In another case, in one minute sufficient effusion hud been poured out to attract the attention of a casual observer.
Should the animal recover from the constitutional effects of the poison, the result of these local changes will be profuse suppuration and sloughing of the parts in which the poison was deposited. Now, simple effusion of blood is very rarely followed by suppuration.
In scurvy and allied diseases, and after injuries, we constantly see effusions of blood rapidly absorbed as recovery proceeds. Again, effusion of blood is seldom attended by pain. Moreover, by using solutions of cobra-poison of different strengths any degree of local mischief can be produced — from an engorgement and ​acute effusion that scarcely differs from blood, to a slight hyperæmia attended with a pale serous-like effusion.
From these considerations it appears evident that the local effect of cobra-poison is simply severe and acute inflammation, to which the pain attending cobra-bite is due, with a more than ordinary tendency to effusion from the blood-vessels. Corroborative testimony to what is here advanced must be present to the mind of everyone who has had much to do in the manipulation of cobra-poison. A very frequent, but involuntary, experiment is to get some of the poison into the eye. Should the circumstance not be at once noticed, so as to permit the eye being washed out immediately, after a very short time a smarting pain is felt in it ; and if it is examined it will be found red and watering, the vessels becoming rapidly enlarged, and, in fact, an acute attack of conjunctivitis with chemosis is set up, which may last for days.
The subject has been specially dwelt on here, as on it can be founded an easy method of deciding whether a person has really been poisoned by a snake. One of the most difficult subjects in connection with snake-bite is to know for certain whether the patient has really been poisoned by a snake or not, for it is clear that unless the venomous snake really injects his poison into the victim there is no danger. Now, the mark of the teeth is no guide, or next to none, because a cobra may not leave a single mark visible to the naked eye; ​and, on the other hand, fanged harmless snakes, like Lycodon and Dipsas, may leave punctures in the skin that might easily be mistaken for the wounds caused by the fangs of venomous snakes. And more misguiding, if possible, than any of these, is the victim's description of the snake. From these various causes it often happens that a man is left without an attempt at treatment because the bite is not visible or does not look like that inflicted by a venomous snake, or because there are no symptoms. Now we know that symptoms may not occur till more than an hour has passed, when all chance of preventing the absorption of the poison has gone. On the other hand severe measures have been resorted to, even ending fatally, when it has been proved afterwards that the subject had not been bitten by a poisonous snake at all. It is therefore of great importance to be enabled to say whether a man has really been poisoned as well as bitten by a snake. This can be done by simply observing the condition of the tissues into which the poison has been injected. No ordinary wounds, not even a poisoned wound such as is received in dissections, can cause the immediate inflammation that is peculiar to snake poison. In a simple or even ordinary poisoned wound a very considerable time would elapse before any marked change would be noticeable. In the vast majority of cases a simple incision through the skin into the subcutaneous areolar tissue will afford certain information whether the case is ​one of poisonous snnke-bite or not; for even though there may be considerable differences in degree as to the amount of inflammation, yet the existence of any at all must indicate that there must be present a cause beyond the mere mechanical injury.
Action of Cobra-Poison on the Nervous System.
That the chief action of cobra-poison is on the nervous system, there can be no doubt. The exact nature of the action, however, is not so clear. The victim of cobra-poisoning just before death is usually an example of very complete general paralysis. Sir Joseph Fayrer and Dr. Brunton, who have written a most elaborate and valuable series of papers on the nature and physiological action of snake-poison, maintain that though the greater part of the nervous system is affected, yet the terminations of the motor nerves suffer especially, and in a very marked manner. They base their reasoning on the results produced by experiments in which the excitability of two nerves of the same animal is tested, one of which has been subjected to the action of the poison, and the other has been kept from contact with the poisoned blood by the limb to which it is distributed being ligatured, the nerve, however, being kept intact. Under these circumstances a great difference will be found in the electric excitability of the two nerves. These experiments have been ​repeated, with, however, some modification in the details.
The electric arrangements were as follows : — A constant difference of potentials was maintained by means of a galvanic battery between the terminals of the primary series of coils of a Thomson's Slide Resistance. Two flexible insulated wires, the free ends of which terminated in platinum needles, and were used as the electrodes, were connected, the one to the zero end of the primary series of coils, and the other to the sliding contact of the secondary coils. By suitably moving the sliding contacts, any desired difference of potentials could thus be established between the electrodes.
Experiment VII.
A frog (Rana tigrina) was killed mechanically at 12.18 P.M., but reflex action continued for some time afterwards.
1.6 P.M. Muscle was found to be infinitely sensitive. Nerve, stimulated with 0.06 volt, produced distinct contraction ; both sides give the same result.
This experiment shows how sensitive muscle and nerve remain for some time after death from purely mechanical causes.
Experiment VIII.
The right thigh of a frog (Rana tiqrina) was ligatured so as to completely prevent the blood circulating in the part below the ligature. The sciatic nerve was not ​included in the ligature. One cubic centimetre of solution of cobra-poison, composed of equal parts of distilled water and fresh cobra-poison was injected into its dorsal sac.
{ti|2em|2.53 P.M. Injection.
It gradually became paralysed till it ceased to show any signs of reflex action.
3.33 P.M. The muscles of the left or poisoned side contracted with 2.97 volts.
3.33½ P M. The muscles of the right or non-poisoned side contracted with 2.16 volts.
3.37 P.M. Nerve of poisoned side caused contraction of muscle when stimulated with 2.7 volts.
3.39 P.M. Ligatured (or non-poisoned) nerve, 1.08 volts.}}
Here there was a marked difference between the poisoned and the non-poisoned side, the non-poisoned side being the more sensitive, but the nerve on the poisoned side had lost its excitability to a greater extent than the muscle. But the paralysis of both the muscle and the nerve was well marked.
Experiment IX.
The right thigh of a frog (Rana tigrina) was ligatured with the exception of its sciatic nerve, and one cubic centimetre of cobra-poison solution, consisting of equal parts of distilled water and fresh cobra-poison, injected into its dorsal sac.
12.48½ P.M. Injection.
12.58 P.M. Reflex movement ceased.
1.40 P.M. Muscles of left or poisoned leg contracted with 2.43 volts.
1.40½ P.M. Muscle of right or non-poisoned leg with 1.89 volts.
1.44½ P.M. Nerve on poisoned side caused contraction in muscle when excited by 10.8 volts.
1.46 PM. Non-poisoned nerve with 0.54 volts.
In this experiment the sensitiveness both of the non-poisoned muscle and nerve, in comparison with that of the poisoned side, was greater than even in the former experiment.
These experiments seem to make it probable that cobra-poison has some special property in deadening the terminations of the motor nerves; and Sir Joseph Fayrer and Dr. Brunton have, in support of this view, given some experiments in which, on irritating the spinal cord with an induced current, contraction was caused in the non-poisoned leg, but not in the poisoned.
The following experiment had for its object to ascertain if the mechanical excitement of the cord could be transmitted through the poisoned nerve.
Experiment X.
A frog {Rana tigrina) had 0.5 cubic centimetre of fresh cobra-poison injected into its dorsal sac at 2.12 P.M., the right thigh, with the exception of the sciatic nerve, having been previously ligatured.
2.20 P.M. Very slight reflex movement.
2.45 P.M. Passing a current through the spinal cord, with interruption produced by means of a key, the muscles of both legs distinctly contracted at 0.5 volt.
2.52 P.M. Spinal cord, mechanically stimulated, gave distinct twitchings in both poisoned and non-poisoned legs.
In all these experiments, as long as the cord possessed power at all, contraction could be excited in either leg provided the nerves had not been mechanically injured, which would rather indicate that the nerves retained their irritability, at the same time that the excitability of the cord was exceedingly quickly lost. Of course a good deal of allowance must be made for the difference; in the method of excitation pursued in the two series of experiments. But though the above experiments go to prove that the excitabihty of the motor nerves lasted as long as that of the spinal cord, yet the difference in the excitability between the two sides in the former experiments showed how powerfully paralysing cobra-poison is. These experiments, then, tend to show that the spinal nervous system is rapidly paralysed by cobra-poison, but that the terminations of the motor nerves only suffer, pari passû, with the cord itself, and the poison has no elective affinity for the ends of the nerves. Nor are the results of the experiments of Sir Joseph Fayrer and Dr. Brunton incompatible with this view.
For when one , thigh of the subject of the experiment ​was ligatured and the other was poisoned, when the cord was excited by a current the stimulus had to he transmitted to the non-poisoned leg through the trunk of the nerve which was unaffected, whereas on the gther leg it had to overcome the resistance induced by the paralysing poison. There is no need to suppose a special effect of the poison on the ends of the motor nerves; the different lengths of the trunks affected would account for a considerable difference. To this we have also to add the paralysing effect on muscle, which, though not so great as on the nerve, is yet not unimportant, and would tell on the same side.
Moreover, it does not necessarily follow that because a nerve to which poison has had access conveys electrical stimuli in a very imperfect manner, or not at all, therefore that the effect of that poison has been to paralyse the nerve. It is unfortunate that the only test we have of the vitality of a nerve is its power of causing contraction in a muscle when irritated by electricity or mechanically. It would be going too far to say, therefore, that because a nerve did not transmit such rude stimuli it was dead; and even if the animal loses the power of withdrawing a limb that is being painfully stimulated, the break in the power of conducting impressions or stimuli may be in any part of the nervous chain necessarily called into requisition in such an action.
A poison that produces death by totally different ​means than paralysis, may yet cause in nerves a complete deadness to stimuli.
Experiment XI.
The right thigh of a frog (Rana tigrina) was tightly ligatured, so as to completely prevent circulation through the limb, the nerve being included. One cubic centimetre of a solution of strychnia, containing two centigrammes of strychnia, was injected into its dorsal sac.
18.53 P.M. Injection.
12.56 P.M. Tetanus.
1.10 P.M. Keflex action ceased.
1.23 P.M. Muscles of right leg infinitely sensitive.
1.25 P.M. Muscles of left (poisoned) leg contract with 0.75 volt.
1.39 P.M. Eight sciatic nerve infinitely sensitive, causes muscular contraction with less than 0.0001 volt.
1.45 P.M. Left sciatic nerve causes contraction with 15 volts.
Now, strychnia certainly does not kill by paralysis, and yet the difference between the poisoned and the non-poisoned sides, in regard to their nerves, was more marked than in cobra-poisoning. In another frog this difference was very pronounced before the strychnia had ceased to produce tetanus, so that it occurs long therefore exhaustion has taken place. The complete cessation of the vital functions through tetanus is the real cause ​of death, and the deadening of the nerves is simply the result of the excessive nervous discharges that have taken place through them. Thus, though the trunk or extremity of the nerve may he found paralysed, this 4oes not prove that paralysis was the cause of death, or that it was the direct result of the action of the poison on the nerve.
In this direction another point must he taken into account. One of the most characteristic features of cobra-poisoning in the human subject, is paralysis of the legs. The patient is unable to walk or to stand, though his arms as yet have not experienced any loss of power. Now it would be difficult to suppose that this was due to the terminations of the motor nerves of the legs becoming paralysed, while those of the arms remained unaffected. It is much more probable that the spinal cord is becoming paralysed ; one of the first effects of which would be that it would lose the power of maintaining the tone aud necessary contraction in the rhany complex groups of muscles on which the upright posture is dependent.
But in cobra-poisoning in dogs, paralysis of the hind-legs without the fore, is rarely seen. In the vast majority of cases, power is lost simultaneously in all four members. As a rule, in those cases in which it has been noticed that the hind-legs have suffered first, the animal has been bitten on the hind-leg, which would always cause a certain amount of lameaess, and difficulty ​difficulty of walking with the hind-quarters, due to the local effect of the poison. But even with this source of fallacy it holds good that in men suffering from cobra-poisoning, paraplegia is a most characteristic symptom; whereas it is exceptional in dogs. Why, then, as a rule should paraplegia occur in men, and not in dogs? Standing and walking are to a very great extent reflex acts. A man when walking places one foot on the ground, and the sensation of contact with the ground, serves as a stimulus to a centre in the cord by which the motor impulse to move the other leg is excited, and paralysis of these few lower centres would at once impair the action. But in dogs the mechanism is very different. They move the fore leg of one side with the hind-leg of the other. It is necessary, then, that the centres governing the movements in these limbs should be coupled, so to speak, together. The stimulus that moves the fore-leg of the one side, has to excite simultaneous movement in the hind-leg of the other. Therefore, all the inferior, or rather posterior, extremity of the cord has to do in the case of the dog, is merely to transmit the motor impulse from the fore-part; whereas, in man, the inferior part of the cord has to translate a sensation into a stimulus to excite movement. It is, therefore, probable that the earliest injury inflicted by cobra-poison on the nervous system is a paralysis of the centres in the lower part of the cord.
It will have been observed that paralysis of the lips, ​tongue, larynx and pharynx, as evinced by inability to retain the saliva within the mouth, by incapacity to move the tongue, or to speak, or to swallow, are very prominent signs of cobra-poisoning both in men and animals. It is singular that the striking resemblance of these symptoms to the disease known as glosso-laryngeal paralysis has not been previously noticed. Now, the preponderance of medical opinion attributes this disease to lesion of certain tracts of the medulla. It cannot be thought, therefore, anything but reasonable to connect both diseases with paralysis of those centres in the medulla oblongata which are so closely associated togetlier, and which are in connexion with the roots of the vagus, the spinal accessory, and the hypo-glossal nerves and the lower nucleus of the facial. But the resemblance does not end here. In both diseases the respiration becomes feebler and feebler, and the victim, at last, dies suffocated. In other words, the lesion in the one case, and the paralysing poison in the other, have invaded the respiratory nucleus so near to the centres they have already destroyed, and have thus rendered the respiratory act difficult, and, at last, impossible. Lastly, after all the lower centres have been completely paralysed, the one by which connection is made with the second, fifth, and seventh nerves still acts, and the eye is closed when touched, and even when approached, after the animal is dependent on artificial respiration for life. For these reasons it seems ​natural to conclude that the principle action of cobra-poison on the nervous system consists of an extinction of function, extending from below upwards, of the various nerve centres constituting the cerebro-spinal system; and though, no doubt, other parts of the nervous system suffer, it is evident that cobra-poison has a special affinity for acting on the respiratory centre, and those other ganglia allied to it in the medulla oblongata, which are in connection with the vagus, the spinal accessory and the hypo-glossal nerves, and that it is directly to this destructive action that we have to attribute death in most cases of cobra-poisoning.
In very rapid cases of poisoning, when a very large quantity of poison has entered the circulation at once, instead of the gradual extinction of function of the cerebro-spinal centres, the poison appears to act almost immediately by stopping the action of the respiratory centre. There is, of course, no time in these cases to watch the gradual extension of the influence of the poison on the nervous system. It also happens that before cobra-poisoning paralyses the cerebro-spinal centres, it first stimulates them, and produces irregular action. This is sometimes very marked in regard to the respiratory centre, when a large quantity of cobra-poison has entered the circulation with considerable
No. I.—TRACINGS of RESPIRATORY MOVEMENTS of a FOWL under GRADUAL COBRA POISONING.
stimulation of the respiratory centre, but they are equally rapidly followed by complete paralysis.
Action of Cobra-Poison on the Respiration.
The action of cobra-poison on the respiratory function deserves the closest attention, as death is generally the direct result of the extinction of this function by the effect of the poison.
The first change that is noticed in the breathing of an animal after the introduction of cobra-poison, is a decided quickening and deepening of the respiratory movement. This effect is no longer to be perceived after section of the vagi, and it has been asserted that the acceleration is due to the stimulation of those nerves by the poison. But section of the vagi is always followed by excessive slowing of the respiratory movement; thus, in dogs, the respirations are generally reduced by one-half. It is not improbable, therefore, that an agent that would somewhat stimulate and accelerate the action of the respiratory centre, would fail in producing this result if administered directly after an operation that had so powerfully retarding effect. The inhibitory effect of section of the vagi may be too great to allow of the accelerating action of the poison being perceived. But this quickening, however ​produced, is merely temporary, and after an interval of uncertain duration the respiration will be found to be slower, and the slowness to increase. The respiratory movement is also lessened in extent. The slowing and lessening of the respiration become at last too great to allow of the blood being properly oxygenated, and, after the usual symptoms characteristic of asphyxiation, the animal dies.
The simplest form in which one can observe the effect of cobra-poison on respiration, is afforded by the common fowl. The stethometric chart marked No. I, gives, in a concise manner, the effects of cobra-poisoning when the action is very gradual. The first line gives the normal respiratory tracing. The main points to be noticed in the succeeding tracings, are the slight quickening first perceived, and the increase of the excursus. These are followed by rapidly increasing retardation, with a certain amount of lessening of the excursus, though the excursus is less affected than the frequency.
No. II.—RESPIRATORY TRACINGS from a FOWL THAT DIED VERY RAPIDLY from a LARGE DOSE of COBRA POISON. the TRACINGS are NEARLY CONTINUOUS.
The respirations before the administration of the poison bear to the respirations at their greatest degree of acceleration, in the tracing IV., the ratio of lour to seven. Chart No. III. is a series of tracings from a large pariah dog, the acceleration followed by retardation, and the accompanying diminution of excursus are well shown; but the nature of the convulsive movements at the end are of great interest. They begin by regular contractions of the respiratory muscles; in the period of their gseatest violence they lose all respiratory character, ​and then gradually fade away in gentler and gentler attempts at inspiration. The cat is an animal that shows a peculiar power of resisting cobra-poison, presenting a marked contrast to the dog. Chart No. IV. is from a cat, in whom this resisting power was prominent. After the retardation of respiration is accomplished, it will be noticed that an occasional deep respiration occurred; it is as if the animal, aware of its lessening breathing power, made conscious efforts to assist respiration. A similar feature appears to have been frequently noticed in the human subject, under like circumstances.
The series of tracings in Chart V. shows graphically the instantly destructive action of cobra-poison on the respiratory function, when a large quantity of the poison suddenly enters the circulation. They are taken from a dog, in whom the following observations were made.
Experiment XII
A powerful pariah dog had one cubic centimetre of fresh cobra-poison injected into its saphena vein. No change was noticed for thirty seconds; at the end of that time normal respiration abruptly stopped, its place being taken by violent and irregular contractions of the respiratory muscles. The action of the heart continued strong, but increased greatly in frequency. Very soon all movement ceased, with the exception of that of the heart, which continued acting for about ten ​Page:AJWall Indian Snake Poisons.djvu/58 ​Page:AJWall Indian Snake Poisons.djvu/61 ​seconds longer. The whole time from injection to death was under 100 seconds.
Chart No. V. is a continuous tracing of the respiration of this animal from the administration of the poison till death. It will he seen that the normal respiratory rhythm is suddenly displaced hy violent alternate upheavings and depressions of the chest walls, and that then all movement at once stops. But it will he noticed that the convulsions, though, of course, irregular, have a distinctly respiratory character. When cobra-poison, then, enters the circulation in large quantity, it stimulates the respiratory centre to such a degree that convulsive action of the respiratory muscles is produced, but after a very brief period complete and permanent paralysis of "the respiratory apparatus is induced. It is worthy of note that rapid as death in this case was, the action of the heart continued after that of the respiration had ceased.
To sum up the different modes in which cobra-poison destroys the respiratory function : — First, almost instantaneous paralysis of the respiratory centre, a primary stimulation of a very violent but very transient character having occurred. This form of death must be exceedingly rare, if it ever occur, in the human subject, as the shortest period of fatal poisoning in man on record appears to have been a little under a quarter of an hour. Secondly, a more gradual method, the poison ​having been more slowly absorbed, when no marked change occurs for some time, and then some irregularity in respiration is noticed, and the respiratory action is soon, but, at the same time, gradually abolished; the convulsions of asphyxia may terminate life. This mode of death is very commonly seen in dogs which have been bitten by vigorous cobras. Lastly, there is that gentle primary stimulation of the respiratory function which is shown only by acceleration, and which is soon followed by lessening and retardation of the respiratory movement, and, finally, by its complete cessation. This appears to be the way in which cobra-poison in the vast majority of cases destroys the human subject.
It should be noted that, though the final convulsions of asphyxia which occur in cobra-poisoning can be removed at will by artificial respiration, and that they recur when the aeration of the blood is stopped, yet that the process of natural respiration cannot be restored by these means after it has once ceased, though the action of the heart and life may be prolonged for some time.
Effect of Cobra-poison on the Circulation, Temperature, Special Senses, Secretion and the Blood.
Cobra-poison cannot be said to exercise a very great effect on the circulation. The heart can be kept acting, and the blood circulating, 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 haa stopped. Absorbed in the ordinary way, cobra-poison appears to slightly nccelerate the heart's action, and it also lessens the blood-pressure, at any rate for some time. Sir Joseph Fayrer and Dr. Brunton have produced death by tetanizing the heart by injecting cobra-poison into the circulation; but this was done by throwing the poison directly into a very large vessel, as the carotid artery or jugular vein, in a small animal — the guinea-pig.
Cobra-poison also appears to have but little influence on the temperature of the body. Sometimes a very slight rise is to be noticed ; generally there is no change, and even a slight fall has been observed. It is probable, therefore, that it has little, if any, effect. The following experiment will show this : —
Experiment XIII.
A healthy pariah dog had a temperature of I02°.9 F. in the rectum. The pulse was 81, and the respira- tions 34. At 12.45 P.M. it was bitten by a vigorous cobra.
12.48 P.M. Lame in bitten leg, which is drawn up.
1 P.M. Seems quite unaffiicted.
1.10 P.M. Affected; staggers when it moves.
1.15 P.M. Temperature in rectum 103°.1 F.
1.16 P.M. Pulse 78, pupils normal.
1.17 P.M. Respirations 28.
1.20 P.M. Slight twitchings of respiratory muscles.
1.23 P.M. Respirations 8.
1.24 P.M. Strong convulsions; micturated; pupils contracted.
1.25 P.M. All respiratory movements stopped ; temperature 103°.1 F.
1.26 P.M. Pupils dilated.
1.27½ P.M. Heart stopped. Dead.
The temperature began to fall directly after death.
In cases of cobra-poisoning of longer duration, we have the disturbing influence of the local inflammation to consider, which would account for some variation in temperature.
In the special senses and their organs no marked change can be seen in cobra-poisoning: as long as consciousness is preserved the victim appears to see and hear perfectly. In regard to the eye there is very little to be noticed. The pupil can be said neither to be dilated nor contracted by the influence of the poison; at the moment of death it dilates widely, while up to that time it responds to light. If life be preserved by artificial respiration the pupils remain somewhat contracted. I once noticed the pupil remain contracted after death from cobra-poisoning, in which long-continued artificial respiration had been resorted to. Whether cobra​poisoning affects accommodation cannot well be known, and what evidence there is appears to be against its being affected. The eye retains its sensitiveness, and the eye-lid the power of closing, for some time after Most other parts are paralysed. But in the human subject drooping of the upper eye-lid is often an early symptom of the action of the poison.
On secretion cobra-poison appears to have considerable influence. It seems as if most secreting structures were stimulated by it. The lachrymal glands act freely during cobra-poisoning. Salivation is a most marked and constant symptom; it is very rarely, indeed, absent in dogs, and it appears to be equally common in man. In dogs, the saliva often runs from the mouth literally in streams; nor in man does it seem much less copious. Should only a small quantity of poison have entered the system, salivation may be the only symptom. The whole of the mucous tract is also apparently in an active state of secretion. After the stomach has been thoroughly emptied by vomiting, the animal will often bring up repeatedly large quantities of mucus, and mucous discharges are also frequently evacuated from the rectum. The respiratory mucous membrane, too, participates. Mucous secretion sometimes flows from the nose, and the air-tubes are not unusually found bathed in fluid. Of its action on the liver and kidneys it is very difiicult to get evidence, as the time before death is generally so short; in the more chronic cases sometimes the kidneys appear ​to act very freely, but sometimes there is a diminution of urine.
There is but little evidence of the effect of cobra-poisoning on the blood. It is, of course, by the blood acting as carrier that the poison is able to reach the system, and the blood of a cobra-poisoned animal is poisonous, also, to another animal. It is clear, therefore, that the poison exists in the blood. That it causes changes in it, there is also evidence. In a man poisoned by a cobra it is very generally, indeed, found that his blood has become incoagulable, though in dogs it is exceptional for this to be the case. Very occasionally, too, the mucous discharges from the body are stained with blood, as if the relation existing between the blood and the tissues had been in some way altered. If, however, the experiments given at the commencement are referred to, it will be seen that in not one was there noted a discharge of blood from a mucous orifice, and they were selected on account of being typical. Still, there are cases on record which prove that discharges of blood, though rare, occasionally occur, perhaps through individual peculiarities.
The interval that occurs between the injection of the poison and the development of the symptoms is, to a certain extent, evidence of blood-change, as the pause can be proved to depend on two factors. The one factor is the time required for the absorption of the poison, for it is lessened by the poison being injected simultaneously ​into several different sites, or into a spot where absorption is very active. The other is clearly dependent on some secondary change produced by the poison, probably in the blood, for which time is necessary; for if the part into which the poison has been injected be excised before the occurrence of a single constitutional symptom, yet, nevertheless, the animal may die apparently as rapidly as if no interference had been attempted, showing that the mere presence of the poison in the blood, even in sufficient quantity to kill, is not capable of producing directly a physiological efFoct. On the other hand, to prevent grave misconception, it should be stated that it is quite possible to save life by excision of the bitten part, if it be done sufficiently quickly to prevent any material absorption.
But that the changes in the blood are not considerable there is abundant evidence. Thus, when an animal has survived the nerve symptoms produced by cobra-poison, it at once passes into a state of complete health, and to suffer no further inconvenience from blood-poisoning or other causes, save the local inflammation produced by the bite. The evidence of this, in the following experiment, is very conclusive : —
Experiment XIV.
A large pariah dog had five milligrammes (${\frac {7}{100}}$ of a gram) of dried cobra-poison dissolved in 0.3 cubic centimetre of distilled water injected into its hind-leg.
12.12 P.M. Injection.
4 P.M. Vomited; no other symptom.
7.30 P.M. Salivated; depressed.
10.15 P.M. Still depressed; salivation slight; respirations 14 per minute.
12.5 A.M. Still salivated; very depressed.
8 A.M. Very weak, hardly able to walk; all the legs equally afifected.
8.25 A.M. Respirations 12; pupils somewhat dilated, but contract to light. Site of injection very red, hot, and swollen.
11.30 A.M. Eespirations 15; frothy salivation.
12 P.M. Rectal temperature 89° C.
12.38 P.M. Pulse about 120, extremely irregular; chewing movement of jaw and lips; salivation considerable.
2.21 P.M. Better; can walk; salivation ceased; ate sparingly.
7.30 P.M. Recovering fast; urinated, no albumen in urine.
8 A.M. Seems quite well ; purulent discharge from site of injection; respirations 20; pulse 120.
The dog was kept under observation, and remained quite well. The normal pulse rate was 90, and respirations 28.
Here, though the most severe nerve symptom were present, they completely passed off, leaving the animal at once in a state of convalescence. There was no ​trace either of permanent nerve injury or of blood poisoning.
The same also occurs in the human subject. I am indebted to Dr. Richards for the following account of a most interesting case which came under his own observation : —
A man named Bamon Das, aged forty years, was bitten by a snake on the shoulder about 3 o'clock in the morning. From his description it was probably the snake termed by the natives of Bengal the "Teutuliah Karís"(a spectacled cobra) about four feet long. He had complained, after the bite, of feeling intoxicated, had vomited, and could neither stand nor speak, though he had continued to be perfectly conscious. At 10 A.M., when Dr. Richards saw him, he was being supported in the sitting posture by two men. Near the posterior border of the deltoid of the left arm were two rather indistinct fang-marks at some considerable distance from each other; one fang-mark, however, more resembled a scratch than a puncture. The arm was painful, hot, and swollen, measuring eleven inches in circumference, whereas the other arm at a similar part measured only nine and a half. On cutting through the punctures the track of the fang was clearly visible, though the staining of the areolar tissue was very slight indeed. He had no power whatever over the eye lids, which had dropped, leaving only the lower parts of the pupils visible. The pupils were perfectly natural, ​and the irides responded. When asked to identify people he pushed his head hack so as to bring the person into the line of vision. He could, in fact, see perfectly well. The hearing was not affected. There was profuse salivation, the saliva streaming down from the corner of his mouth. The lower lip had drooped. He could speak but very indistinctly, so indistinctly that his friends had to ask him to repeat what he said. The intonation was peculiarly nasal, much resembling that of persons who have lost part of their palate. The lips were not used in his endeavour to pronounce his name, consequently the labial b was omitted, and he answered with a very indistinct and nasal "Aon Dás." On attempting to swallow some water it was returned through the nostrils. He was unable to clear his throat, which caused him some distress. He felt some difficulty in breathing, though the respiration was but slightly embarrassed. The superficial temporal and frontal veins were very distinct and tortuous, being gorged with blood. He could not walk himself, but if supported walked with an unsteady gait, though he had perfect control over his upper extremities. Still felt intoxicated and his body hot. Pulse 96, full and strong. Temperature 100°.5 F. Occasional retching.
11.30 A.M. Slightly better; still feels intoxicated; temperature 101°.1 F.
1 P.M. Temperature 101°.5 F.
2.30 P.M. Arm a little more swollen — now measures
Feels a little sick, and the veins about the face are still rather gorged. Now speaks distinctly, and can fallow. Suffering rather severely from the pain in the arm.
From this time the arm got gradually better, and the man completely recovered.
In this case we have an example of severe cobra-poisoning, well described, in which the nerve symptoms were fully developed, and yet, when they had passed away, the man was at once in a state of thorough and complete recovery.
In the published report of the Snake Commission, by Drs. Ewart, Richards and Mackenzie, in the experiments given as to the least amount of poison required to kill, no animal died after thirty-two hours; and the one case that lived that time, it is clear from the history, died of nerve affection. Of the rest that survived, though many of them had the most serious nerve symptoms, not one appears to have given any evidence of blood alteration. The microscope, also, gives no evidence of structural change in the blood. In cobra-poisoning, also, albumen in the urine is unknown. In animals that have suffered most severely from nerve symptoms, in which I have tested the urine, albumen has not been present in a single instance, either in fatal or non-fatal oases. When, however, artificial ​respiration has been performed for some time, it is not unusual for blood to be present in the urine; but if the kidneys be examined in these cases the wonder will be, not that blood was found in the urine, but that any urine was secreted at all to mix with the blood, so great is the renal congestion. This circumstance, therefore, can hardly be taken as evidence of blood change.
In spite, then, of occasional discharges of blood from mucous surfaces, and that the blood of man is generally found fluid after death, if we take into consideration the facts that death, except from nerve symptoms, is unrecorded ; that after the subject has recovered from the nerve effects, he at once regains his usual health, sequelae being unknown, at least if we trust the available evidence — always excepting the local results of cobra-bite which are most severe; and that in the vast majority of cases there is no symptom of serious blood-poisoning even during the occurrence of the nerve symptoms; also that the kidneys give no evidence of altered relation to the blood; and that, as a rule, the coagulability of the blood is not destroyed in animals: we may conclude that though cobra-venom is a nerve poison of surpassing deadliness, as a blood poison it is not an agent of much power.