April 23, 1896] 



NATURE 



595 



the quantity of venom that has been introduced into the body 

 in the process of producing protection, the greater is the anti- 

 VL-nomous power of the blood-serum, and therefore the larger is 

 the production of the antivenene. While not an actual proof, 

 tills circumstance is at the same time in harmony with the 

 supposition that the antivenene may actually be a constituent 

 of the venom itself. The difficulties encountered in the separa- 

 tion by chemical methods of the several constituents of venom 

 are so great, that it is not probable that the only proof or dis- 

 proof of this supposition will soon be obtained by chemical 

 analysis. Some physiological experiments which I have made 

 seem, however, to go a long way in supplying the demonstration, 

 which in the meantime has not been obtained from chemistry. 



With the object of determining, in the first place, if the still 

 disputed statement is correct that serpents' venom is inert, or 

 nearly so, when introduced into the stomach of an animal, 

 cobra venom was administered, in a series of gradually increas- 

 ing doses, to a cat, until finally it had received a single dose 

 eighty times larger than the minimum-lethal ; and to each of six 

 while rats, single doses corresponding to lo, 20, 40, 300, 600, 

 and 1000 times the minimum-lethal, if given by subcutaneous 

 injection. Although no poisonous symptoms were produced in 

 the animals by even the largest of these enormous quantities, it 

 was found that the cat had so far been protected, that it could 

 afterwards receive, by subcutaneous injection, one and-a-half the 

 minimum-lethal dose of cobra venom, without any other injury 

 than some localised irritation at the seat of injection ; and that 

 the white rat, into whose stomach 1000 times the minimum- 

 lethal dose had been introduced by one administration, survived 

 perfectly, when seven days afterwards slightly more than the 

 minimum-lethal dose of venom was injected under the skin. 



It was also found that the blood-serum of the cat was 

 definitely antivenomous, and the curious further fact was ascer- 

 tained that her progeny had acquired protection through the 

 milk supplied by the protected mother, thus supplying a scientific 

 foundation for a half-admitted conviction, expressed by Wendell 

 Holmes throughout his " Romance of Destiny," in regard to the 

 heroine Elsie Venner. 



These significant facts have been extended in a number of 

 other experiments on white rats. In one group of experiments, 

 each animal received, by stomach administration, 500 times the 

 minimum-lethal, if given subcutaneously ; and, as before, no 

 toxic symptoms were observed. On the day following this 

 administration, three of the animals received subcutaneously 

 one-and-a-half the minimum lethal dose of the same cobra 

 venom, and they all recovered. In one of the other three 

 animals, however, death was caused by this dose, when it was 

 injected only three hours after the stomach administration ; in 

 a second, when this dose was injected two days after the 

 stomach administration ; and in the third, when nearly twice the 

 minimum-lethal was injected twenty-four hours after the stomach 

 administration. 



In a second group of experiments, a dose of cobra venom 

 equivalent to \QOO times the minimum-lethal by subcutaneous 

 injection was introduced into the stoimach. On several occasions 

 in which this had been done, an injection under the skin of one- 

 and-a-half the minimum-lethal dose of venom made, in some 

 experiments, two days, and in others three days afterwards, 

 resulted in the recovery of the animals. As was anticipated, 

 this large quantity introduced into the stomach, conferred im- 

 munity against only certain lethal doses of venom, and, for each 

 lethal dose capable of being rendered innocuous, only within 

 certain definable intervals of time. 



The extraordinary result was thus obtained that serpents' 

 venom introduced into the stomach in large quantity— in a 

 quantity, which if injected under the skin would be sufficient to 

 kill 1000 animals of the same species and weight — while it 

 failed to produce any definite symptoms of poisoning, neverthe- 

 less produced complete protection against the lethal effect of 

 doses of venom more than sufficient to kill the animals. There 

 is a probable significance, further, in the general resemblance 

 between the results of these experiments and those already 

 described in which antivenene, and not venom, was introduced 

 into the stomach. The bearing of these facts is obvious upon " 

 discussions relating to the production of immunisation agamst 

 the toxines of diseases and to the origin of the antidotal qualities 

 of the blood-serum used in their treatment. It is difficult to 

 account for them otherwise than by supposing that the venom 

 while in the stomach had been subjected to a process of analysis, 

 by which the constituents which are poisonous had failed to be 



NO. 1382. VOL. 53I 



absorbed into the blood, or had been destroyed in the stomach 

 or upper part of the alimentary canal, while the constituent or 

 constituents which are antivenomcus, or rather antidotal, had 

 passed into the blood, in sufficient quantity to protect the animals 

 against otherwise lethal administrations of venom. I confidently 

 anticipate that this natural process of analysis will, by-and- 

 by, be successfully repeated outside of the body by chemical 

 methods. 



It is further to be observed that by stomach administrations a 

 degree of protection was acquired in a few hours against lethal 

 doses, such as cannot be attained until after the lapse of several 

 weeks by the method of injecting under, the skin a succession of 

 gradually increasing doses of venom. In circumstances, which 

 are no doubt exceptional, the application of this method may 

 therefore acquire some practical value. 



Early this evening, I had occasion to point out that the leading 

 facts connected with immunisation or protection, now being 

 advanced as scientific novelties, had apparently been ascertained 

 and practically applied for centuries by savage and uncultured 

 tribes and sects in various parts of the world. In regard to the 

 results I have last described, also, I discover that I have been 

 anticipated by a long-existing and even now prevailing practice 

 of unlearned savages. I have found in the Lancet of 1886, an 

 interesting note by Mr. Alford Bolton, containing the following : 

 " The most deadly snakes here are the puff-adders, the yellow 

 cobra capellas, the horn-snakes, and the night adders. Whilst fre- 

 quently hearing of horses and cattle rapidly succumbing to the 

 bites of these snakes, it appeared strange that the natives them- 

 selves, who mostly ramble about the Veldt almost naked, seldom 

 or never appeared to suffer any further inconvenience from the 

 bites of poisonous snakes than would be usual from any accident 

 which would cause a local inflammation ; and, on close inquiry, 

 I found that the natives in Bushmanland, Namaqualand, 

 Dumaraland, and the Kalakari, are in the habit of extracting the 

 poison-gland from the snake immediately it is killed, squeezing 

 it into their mouths, and drinking the secretion, and that they 

 thereby appear to acquire absolute immunity from the effiscts of 

 snake-bites." He proceeds to describe the native treatment of 

 snake-bite, and then adds : " Having a month ago seen a native 

 named Snellsteve, who is a snake-poison drinker and collector, 

 put his hand mto a box containing two yellow cobras, and 

 several horn- and night-adders, in doing which he was severely 

 bitten, and has never since suffered anything more than a little 

 pain, such as might be caused by any trivial mishap, I feel 

 I can no longer refuse to believe in the efficacy of the snake 

 virus itself as a remedy against snake-poison." Among several 

 communications which I have recently received on the subject, 

 is one from Dr. Knobel, of Pretoria, who writes that when a 

 boy he came into frequent association with a Bushman shepherd, 

 who informed him that he had for years been in the habit of 

 swallowing small quantities of the dried venom-glands of serpents, 

 and he averred that by doing so he obtained protection against 

 serpents' bites, for he had often been bitten without any other 

 ill effect than that an irritable wound was produced. He stated 

 that the swallowed venom of the cobra produced greater pro- 

 tection than the venoms of less poisonous serpents ; and that 

 not only was this benefit produced by the swallowing of venom, 

 but that there was also produced an exciting intoxication, differ- 

 ing from that of Indian hemp in so far that the venom always 

 produced the same degree of intoxication with a definite quantity, 

 however frequently it was taken, while the effects of the Indian 

 hemp were gradually lessened by repetition. Another corres- 

 pondent. Dr. Laurence, of Cape Colony, writes that a Kaffir boy, 

 " aged about twenty-five years, frequently brings me for sale 

 snakes of all kinds. ... I have frequently seen this boy take 

 hold of some most deadly snakes, especially the well-known 

 puff-adder, which he will allow to bite him with impunity. 

 Yesterday, I obtained from him what he states as the reason why 

 the poison did not harm him. When a little boy, while walking 

 in the Veldt, a puff-adder fastened on his leg. He shook it off, 

 calling to his father, who a few minutes after killed the puff- 

 adder and removed the poison glands. He then made small 

 paper pellets and dipped them in the poison, and administered 

 one occasionally to the boy, who stated that that cured him. 

 He expressed his wilUngness to let any snake bite him." Several 

 other letters I have received describe similar events, and also 

 confirm the statement of Dr. Knobel, that serpents' venom pro- 

 duces intoxicating effects in man, evidences of which have been 

 observed in many of the experiments made by me on the lower 

 animals. 



