At the base of each fang, and extending from a point just beneath the nostril, backward two-thirds the distance to the commissure of the mouth, is the poison gland, analogous to the salivary glands of man, that secretes a pure, mucous saliva, and also a pale straw-colored, half-oleaginous fluid, the venom proper. Within the gland, venom and saliva are mingled in varying proportions coincidently with circumstances; but the former slowly distills away and finds lodgment in the central portion of the excretory duct, that along its middle is dilated to form a bulb-like receptacle, and where only it may be obtained in perfect purity.
When the reptile is passive, the fangs are arranged to lie backward along the jaw, concealed by the membrane of the mouth, and thus offer no impediment to deglutition. Close inspection, however, at once reveals not only their presence, but also several rudimentary ones to supply their place in case of injury or accident. The bulb of the duct, too, is surrounded by a double aponeurotic capsule, of which the outermost and strongest layer is in connection with a muscle by whose action both duct and gland are compressed at will, conveying the secretion into the basal aperture of the fang, at the same time refilling the bulb.
When enraged and assuming the offensive and defensive, the reptile draws the posterior portion of its body into a coil or spiral, whereby the act of straightening, in which it hurls itself forward to nearly its full length, lends force to the blow, and at the same instant the fangs are erected, drawn forward in a reverse plane, permitting the points to look outward beyond the lips. The action of the compressor muscles is contemporaneous with the blow inflicted, the venom being injected with considerable violence through the apical outlets of the fangs, and into the bottom of the wound. If the object is not attained, the venom may be thrown to considerable distances, falling in drops; and Sir Arthur Cunynghame in a recent work on South Africa relates that he was cautioned not to approach a huge cobra of six feet or more in length in its death agony, lest it should hurl venom in his eyes and create blindness; he afterward found that an officer of Her Majesty's XV. Regiment had been thus injured at a distance of forty-five feet, and did not recover his eyesight for more than a week.[1]
With the infliction of the stroke and expression of its venom, the creature usually attempts to reverse its fangs in the wound, thereby dragging through and lacerating the flesh; an ingenious bit of devilishness hardly to be expected from so low a form of organism; but its frequent neglect proves it by no means mechanical, and it frequently occurs that the animal bitten drags the reptile after it a short distance, or causes it to leave its fangs in the wound. Some serpents also, as the fer de lance, black mamba, and water moccasin, are apparently actuated by most vindictive motives, and coil themselves about the part bitten, clinging with leech-like tenacity and resisting all attempts at removal. Two gentlemen of San Antonio, Texas,[2] who were bitten by rattlesnakes, subsequently asserted that after having inflicted all possible injury, the reptiles scampered away with unmistakable manifestations of pleasure. "Snakes," remarked one of the victims, "usually glide smoothly away with the entire body prone to the ground; but the fellow I encountered traveled off with an up and down wave-like motion, as if thrilled with delight, and then, getting under a large rock where he was safe from pursuit, he turned, and raising his head aloft waved it to and fro, as if saying. 'Don't you feel good now?' It would require but a brief stretch of the imagination to constitute that serpent a veritable descendant of the old Devil himself."
As the first blow commonly exhausts the receptacle of the duct, a second (the venom being more or less mingled and diluted by the salivary secretion) is comparatively less fatal in results; and each successive repetition correspondingly inoffensive until finally nothing but pure mucus is ejected. Nevertheless, when thoroughly aroused, the reptile is enabled to constantly hurl a secretion, since both rage and hunger swell the glands to enormous size, and stimulate to extraordinary activity—a fortuitous circumstance to which many an unfortunate is doubtless indebted for his life. The removal of a fang, however, affects its gland to a degree that it becomes almost inoperative, until such a time as a new tooth is grown, and again calls it into action, which is commonly but a few weeks at most; and a person purchasing a poisonous serpent under the supposition that it has been rendered innocuous, will do well to keep watch of its mouth lest he be some time taken unaware. It may be rendered permanently harmless, however, by first removing the fang, and then cauterizing the duct by means of a needle or wire, heated to redness; when for experimental purposes the gland may be stimulated, and the virus drawn off by means of a fine-pointed syringe.
In what the venom consists more than has already been described, we are not permitted to know. It dries under exposure to air in small scales, is soluble in water but not in alcohol, slightly reddens litmus paper, and long retains its noxious properties. It has no acrid or burning taste, and but little if any odor; the tongue pronounces it inoffensive, and the mucous surface of the alimentary track is proof against it, and it has been swallowed in considerable quantities without deleterious result—all the poison that could be extracted from a half dozen of the largest and most virile reptiles was powerless in any way to affect an unfledged bird when poured into its open beak. Chemistry is not only powerless to solve the enigma of its action, and the microscope to detect its presence, but pathology is at fault to explain the reason of its deadly effect; and all that we know is that when introduced even in most minute quantities into an open wound, the blood is dissolved, so to speak, and the stream of life paralyzed with an almost incredible rapidity. Without test or antidote, terror has led to blind, fanatical empiricism, necessarily attended with no little injury in the search for specifics, and it may be reasonably asserted that no substance can be named so inert and worthless as not to have been recommended, or so disgusting as not to have been employed; nor is any practice too absurd to find favor and adherents even among the most enlightened of the medical profession, who have rung all the changes of the therapeutical gamut from serpentaria[3] and boneset to guaco, cimicifugia, and Aristolochia India to curare, alum, chalk, and mercury to arsenic; and in the way of surgical dressings and appliances everything from poultices of human fæces,[4] burying the part bitten in fresh earth,[5] or thrusting the member or entire person into the entrails of living animals, to cupping, ligatures, escharotics, and the moxa.
Although the wounds of venomous serpents are frequently attended with fatal results, such are not necessarily invariable. There are times and seasons when all reptiles are sluggish and inactive, and when they inflict comparatively trifling injuries; and the poison is much less virulent at certain periods than others—during chilling weather for instance, or when exhausted by repeated bites in securing sustenance. Young and small serpents, too, are less virile than large and more aged specimens, and it has likewise been observed that death is more apt to follow when the poison is received at the beginning or during the continuance of the heated term.
The action of the venom is commonly so swift that its effects are manifested almost immediately after inoculation, being at once conveyed by the circulatory system to the great nervous centers of the body, resulting in rapid paralysis of such organs as are supplied with motive power from these sources; its physiological and toxicological realizations being more or less speedy accordingly as it is applied near or remote from these centers, or infused into the capillary or the venous circulation. Usually, too, an unfortunate experiences, perhaps instantaneously, an intense burning pain in the member lacerated, which is succeeded by vertigo, nausea, retching, fainting, coldness, and collapse; the part bitten swells, becomes discolored, or spotted over its surface with livid blotches, that may, ultimately, extend to the greater portion of the body, while the poison appears to effect a greater or less disorganization of the blood, not by coagulating its fibrine as Fontana surmised, but in dissolving, attenuating, and altering the form of its corpuscles, whose integrity is so essential to life, causing them to adhere to one another, and to the walls of the vessels by which they are conveyed; being no longer able to traverse the capillaries, œdema is produced, followed by the peculiar livid blush. Shakespeare would appear to have had intuitive perception of the nature of such subtle poison, when he caused the ghost to describe to Hamlet
"The leprous distillment whose effect
Bears such an enmity to the blood of man
That swift as quicksilver, it courses through
The natural gates and alleys of the body
And with sudden vigor it doth posset
And curd like eager droppings into milk,
The thin and wholesome blood: so did it mine
And a most instant tetter marked about
Most lazar like, with vile and loathsome crust
All my smooth body."
It is not to be supposed, however, that all or even a major portion of the blood disks require to be changed or destroyed to produce a fatal result, since death may supervene long before such a consummation can be realized. It is the capillary circulation that suffers chiefly, since the very size and caliber of the heart cavities and trunk vessels afford them comparative immunity. But of the greatly dissolved and disorganized condition of the blood that may occur secondarily, we have evidences in the passive hæmorrhages that attack those that have recovered from the immediate effects of serpent poisoning, following or coincident with subsidence of swelling and induration; and, as with scurvy, bleeding may occur from the mouth, throat, lungs, nose, and bowels, or from ulcerated surfaces and superficial wounds, or all together, defying all styptics and hæmastatics. In a case occurring under the care of Dr. David Brainerd in the Illinois General Hospital,[6] blood flowed from the gums in great profusion, and on examination was found destitute, even under the microscope, of the faintest indications of fibrine—the principle upon which coagulation depends. The breath, moreover, gave most sickening exhalations, indicative of decomposition, producing serious illness in those exposed for any length of time to its influence. We may add, among other sequelæ, aside from death produced through primary and secondary effects, paralysis, loss of nerve power, impotence, hæmorrhage, even mortification or gangrene.