« AnkstesnisTęsti »
It has followed in man within a minute, but organ thus disordered. These phenomena unless the dose given be enormous, or by make the second stage of poisoning, and with chance enters a vein, this is very unlikely. The them there is, in finally fatal cases, a continuous bite is, however, popularly believed to be and increasing damage to the nerve centers that mortal, and therefore every case of recovery keep us alive by energizing the muscles which gives credit to some remedy, for it is a maxim move the chest walls and so give rise to the with physicians that the incurable and the filling and emptying of the lungs. easily relievable maladies are those which have When a physiologist speaks of a nerve cenmost remedies assigned to them.
ter he means by this a group of minute nerve Usually the animal struck gives a cry, and cells, and such a group he is apt to call a very soon becomes dull and languid. The ganglion, labeling it with the name of the disheart, at first enfeebled, soon recovers, the res- tant organ or the function to which it gives pirations become slower and weaker and more energy. Much alike in appearance, one ganweak, paralysis seizes the hind legs, the chest glion keeps the chest in motion, one influences becomes motionless, and at last death follows, the heart, one regulates the temperature of the usually without convulsions. Observe how body. When we throw into the circulation a little this tells us. Mere outward observation poison, it comes into contact with all of these gives us but slight explanatory help. If the numerous governing centers; but it does not animal should chance to survive over a half- trouble all of them alike. It has, as a rule, a hour, the part bitten swells, darkens, and fatal affection for one only, or far more for one within a few hours the whole limb may be than for another. Why venom should, as if by soaked to the bone with blood, which has choice, almost instantly enfeeble the ganglia somehow gotten out of the vessels and re- which keep us breathing, none can say. By and mained fluid in place of clotting. What is at by it also in turn disturbs other groups of nerve first local by and by becomes general, and cells, but its deadliest influence falls on the soon the blood everywhere ceases to have respiratory mechanism. The nerve cells thus power to coagulate. Then leakages of the attacked undergo no visible change; yet some vital fluid occur from the gums or into the mysterious alteration is present. Probably they walls of the heart, the lungs, brain, and intes- lose power to give out their waste products and lines, and give rise to a puzzling variety of to re-absorb from the blood the material needsymptoms, according to the nature of the •ful to sustain their local life and activity. At all events the evil done is grave, and when the are more dreaded. With us the rattlesnake dose of venom is large, death becomes cer- leads for capacity to kill, and the copperhead tain, the animal bitten perishing by slow suffo- and the moccasin come in order after him. The cation.
popular verdict puts the copperhead above the The deadly apothecary does not succumb crotalus, but it is wrong, as the above classifito his own drugs. I have over and over in- cation rests on careful comparisons of the relajected under the skin of a rattlesnake its own tive poisoning power of these snakes. venom or that of a moccasin, or of another The popular notion of the immunity of some crotalus; but in no case have I seen a death animals has little foundation. Cold-blooded
result. Why should this be? Other and non- creatures die slowly from snake bite, and the venomous snakes die readily of venom poison- hog escapes only because he does not get seing. The many noxious compounds man carries riously bitten. His bristles, tough skin, and in his liver, gastric glands, or thyroid gland are clever mode of attack save him. Little pigs fatal if they enter the blood in large amount. are often bitten and die like other creatures. There is, indeed, scarcely an organ of his body We have never been able to poison plants with which is not a possible source of poison to him, snake venom. the sole question being as to his constant com- Practically speaking, there is something more petency to rid himself of the fractional doses to be said as to the question of relative toxever passing into and out of his blood and to icity. The size of the serpent, the time which secure himself against certain products which has elapsed since it has bitten, determine also are not meant at any time to pass out of the the extent of the damage it can do. A snake issues of certain organs of the body into the which has lately bitten two or three times is ill hurrying currents of the circulation.
provided with poison, but captive snakes long But to all creatures save itself the venomous undisturbed are apt to inflict fatal wounds. serpent is noxious in varying degrees. Cer- The serpents used in our recent research tainly the cobla surpasses as a poisoner all of were brought chiefly from Florida by the poour American snakes. In India other serpents tent aid of the Smithsonian Institution, and the
dried venom of the cobra was procured from heat, it is found to be innocuous. The clear India through the assistance of her Majesty's fluid which passes through the filter is, however, Indian Government, and more largely by the poisonous, but does not cause much local effect. private aid of Vincent Richards, Esq. The As a whole the poison has been damaged by living snakes reached us in coffee-bags secured heat, presumably because one or more of its by strings, the sacks having been placed in a ingredients had been injured by heat. The perforated box. When they came we opened next step is to learn if the substance made solid the case, undid the strings and tumbled the and inert by boiling cannot be separated in poisoners into a box some five feet deep. There some other way and in such a form as will they lived very well if provided with water; and leave it also poisonous. coiled in corners, or piled in numbers one on All soluble substances are divisible into two another, they lay sluggish and inert until danger classes, one of which will pass through an threatened. There were half a dozen of these animal membrane into a current of pure water snake cages in our laboratory and at times they and one of which will not. Those which can contained a hundred snakes, each genus or so pass are said to be dialysable, and the filter species having its own box. If disturbed, the is known as a dialyser, and the process is called rattlers were apt to start a chorus which was dialysis. We dissolve some of the poison in somewhat appalling to strangers.
water and put it in an inverted funnel, the When we desire to collect venom, we use wide mouth of which, being covered with a the snake loop. With it a serpent is caught thin animal membrane, is placed in distilled by the neck and lifted up to the top of the water. Under these circumstances the water box. The lip of a saucer is then slipped into goes through the membrane and dilutes the the snake's mouth. Angry at this liberty, it Huid above it and certain substances pass out lifts its fangs, which catch on the inner edge of to the water. the saucer, against which the serpent bites fu- The matter which thus finds its way out riously again and again. As it does so a thin to the water is said to be dialysable. When yellow fluid squirts out of the perforation near examined it proves to be poisonous — to be to the needle-like end of the fangs. We slacken uncoagulable by heat, and to be the same as the loop, let the snake fall into a box cage, and the matter left unaltered when we boil the seize a second, and a third, until we have all the diluted poison for a few moments. This venom we desire. It is innocent-looking enough. substance resembles the albuminous matter In water a drop of it sinks, whitening as it falls. which is formed when gastric juice digests It has no smell and no taste. A boiling heat white of egg; and as the material so obclots it as it does white of egg, for, like that tained is called peptone, we named our prodbody, it is albuminous in its nature. If we dry uct which passed through the dialyser to water it with care there is the same resemblance to venom peptone. egg albumen in its shining, yellow scales. Once As the thinner water enters the dialyser and desiccated it keeps well, as it does also in glyc- the peptone goes out, within the vessel there erine or in alcohol.
falls down a white substance, which is easily When I first studied this strange poison I redissolved if we add a little common salt. It thought of it as a single albuminous body. falls out of solution because the salts belongAs such it had always been regarded since ing to venom and which keep the white matter it had been proved by Prince Bonaparte to dissolved are, like all saline substances, diabelong to the albumens. When once I chanced lysable and pass out along with the peptone. to think that venom might be a complex fluid, This white precipitate has certain likenesses holding in solution more than one poison, rea- to the albuminous bodies known as globulin, sons for such a belief multiplied, and so ex- and of which there are several kinds in our cited my interest that, in 1882, with Professor bodies. That which thus falls out of the soluReichert's aid, 'I began to put my theory to the tion of venom we named venom globulin. It sharp test of experiment.
was to be had also in a simpler way. When To prove in the outside laboratory what the we add plenty of pure water to clear fresh inside mental laboratory has comfortably set- venom the water added makes the whole fluid tled is not always easy, and many months of relatively less salt and a white matter falls careful research' were required before the an- down. When this is separated and examined swer came to us. I will try to make clear our it proves to be the same as that left within the methods and results. When a little of the dialyser. Other matters of like nature but less venom is placed in sufficient water it dissolves important are found in some snake venoms, readily. If now we heat the solution a coagu- but essentially all examined by us contained lation takes place, just such as happens when at least two albuminous matters. white of egg hardens on boiling. If by means Mix these two in pure water with a little of a filter we separate this substance clotted by common salt and you practically reconstruct
a venom—the other ingredients are of less in that of the rattlesnake. In the Indian serpent moment.
it constitutes, however, nearly the whole of the If we put venom peptone under the skin of toxic albumen present, there being but two per a living animal it behaves much as boiled cent. of the other element in question. The venom does. The local injury it causes is at venom peptone of the cobra is also a far more first slight. Little or no blood oozes forth, but, active agent than the substance which corif the animal survive, in an hour or two a responds to it in the venom of our crotalus, watery swelling is seen, the tissues soften as if although chemically we can see but little difthey were melted or dissolved, a horribly swift ference between the two; since venom peptone putrefaction occurs, and the tissues near and passes with ease through membranes, and hence far swarm with the little rod-like bodies known is rapidly absorbed, cobra poison may not alas bacteria, which are the essential accompani- ways be swallowed with impunity, whereas it ment and cause of putrefaction. Meanwhile is possible to feed a pigeon on crotalus venom the breath-sustaining centers become weak, day after day and see it live unhurt. and cease to respond by rhythmical effluxes of While rattlesnake venom owes a part of its energy to the various excitations which stimu- activity to venom peptone, its peculiar virulence late the muscles so as to cause them to move and destructiveness belong chiefly to venom the chest. The animal dies from failure to globulin, of which it has relatively nearly twenbreathe. Internal bleeding is rare and slight, ty-five per cent.— fifteen times as much as in nor are the changes in the blood at all remark- cobra. Venom globulin, like the peptone poison, able.
at first and briefly enfeebles the heart, but Venom peptone is present in cobra poison, and next attacks the respiratory centers, and finally
paralyzes the spinal ganglia. When separated the smallest of vessels, is a constant source of and redissolved in a weak and saline solution wonder to him who sees it. Venom peptone in with water it is a most potent poison; and solution disturbs this local food stream but besides its influence on the centers which little. Venom globulin exhibits its effects with sustain life, it has, soon or late, distinctive difficulty, and solutions of dry venom cause but effects on almost all the tissues which some- slight and tardy results. If, however, we touch what resemble the changes seen in certain the thin membrane with fresh rattlesnake maladies, such as yellow fever; yet that which poison, in a few minutes the delicate little cells, in them exacts days is brought about from which are like a thatch on the inside of the globulin poisoning within an hour or less. At capillary vessels, seem to be roughened, and the spot where we inject globulin the vessels become less transparent. Then, abruptly, here give way and pour out blood which cannot and there a drop of blood oozes out. Presently clot, and this change by and by occurs here the fanlike expansion of the minute vessels we and there throughout any or every organ of are watching begins to look like a bunch of red the body, so that at last the blood becomes grapes, as these tiny blood points increase in what physicians call diffluent, and may remain size and number, until at last the whole field until it decays, free from the clots usually seen of view is covered with escaped blood. It is in the healthy fluids when drawn and allowed then a question of time as to how long it will · to stand.
be before the same disintegration of vessels, Thus it is that, because the cobra has little and the same loss of power in the blood to clot, venom globulin and the rattlesnake much, the occur in hundreds of places remote from the local appearances of the bite in either are spot first poisoned. readily recognizable. Then, also, as the Indian If after poisoning an animal we examine the snake has much venom peptone and our serpent blood cells at intervals, we find that they very little, the former kills more surely and sooner, early lose their usual flat, disklike aspect, and and does not cause the blood to stay fluid, so become smaller and round. They also acquire that in most cases the general phenomena for a time a singular stickiness and elasticity, would also enable us to say which snake had so that they adhere in masses, and when combitten. Certain other Indian snakes give us pressed spindle out, and then run together symptoms like those caused by the bite of our anew when we cease to subject them to presscrotalidæ, and probably will be found to re- ure. semble them in the composition of their venoms. The power of venoms to hasten and favor While we can thus separate and analyze the putrescence must have something to do with influence of the two poisons found so far in all the symptoms which occur when death takes venoms examined by us, neither alone occasions place after a long interval, as a day or two, or .the tremendous and perfect effects seen when when slow recovery occurs. This tendency is both are combined by mischievous nature in a an indirect effect. If we sterilize venom,—that suitable solution. Nor, indeed, is the poison is, subject it to dry heat until all germs are deever quite so effective after it has been once stroyed,- and leave it then in contact with dried and redissolved for experimental use. sterilized soup guarded from the germs afloat
There are vegetable poisons which possess in the air, no putrefaction ensues; but if to this power to destroy life by enfeebling the respira- sterilized broth we add venom not so deprived tory nerve centers; but we know of no poison of bacterial germs, putrefaction is hastened at save snake venom which has the ability to ruin a rate never seen under other circumstances. in a few minutes the capacity of the lesser ves- Now, as bacteria are always present in fresh sels to keep the moving blood within their guard- venom, enough enter a wound to account for ing walls. Our every function—nay, life itself the fact that animals envenomed swarm within
- depends on the blood being so restrained an hour or two with the organisms which If by accident a drop or two of normal blood cause putrefaction. Their rate of increase is escape from a small vessel, instantly the blood inconceivably great, and seems to be favored clots and tends to cork up the tiny tear through by the poison, which provides them with some which it came. Venom not only seems to rot mysterious conditions of growth. Thus it is the vessels, but it also makes the blood fluid, that the blood, the nervous centers, the vessels, and so facilitates the hemorrhages of which it are all in turn attacked by these fearfully deis the primary cause. To study this singular structive poisons, and that at last putrescent process of destruction closely a small animal changes may be added to the causes of a was so completely etherized as to cease to feel multiform group of perplexing phenomena. pain, and a loop of its intestinal cover called The general reader will ask what good has the peritoneum was examined with the micro- come out of these clearer views as to the scope. The spectacle of the blood globules mechanism of this poisoning. Our own labors driven swiftly through transparent capillaries, and the brilliant work of Fayrer, Lauder-Brun
Vol. XXXVIII.- 67.