596 



NA TURE 



[April 23, 1896 



The results of the experiments in which the venom was 

 introduced into the stomach, probably also afford an explana- 

 tion of the protection enjoyed by certain snake-charmers, as 

 well as by other individuals who claim to be protected, whether 

 members of special sects or not ; for although inoculation of the 

 venom is apparently sometimes -practised by them, and pro- 

 tection is no doubt assisted and maintained by the bites, which 

 with impunity they frequently receive, they are known also to 

 swallow the venom or the dried poison-glands containing it. 



These experiments also seem to throw a new light upon the 

 clearly established protection possessed by venomous serpents 

 against their own venom. They suggested the importance of 

 determining if the blood-serum of venomous serpents contains, 

 as does that of artificially protected animals, an actual substance 

 possessing anti venomous properties. 



In order to arrive at some definite conclusions on this subject, 

 I last year obtained from India several living specimens of the 

 Hamadryad (Ophiophagris elaps), a serpent of greater size and 

 more aggressive disposition than the cobra, and reputed to be 

 as deadly as it. From the blood of several of these serpents a 

 serum was separated, which when dried gave a product having 

 the same physical characters as the antivenene from artificially 

 protected animals. It was tested against cobra venom, both 

 when mixed with rather more than a minimum-lethal dose, and 

 also when injected thirty minutes after this lethal dose of cobra 

 venom. In the former case, "25 cc. per kilogramme of this 

 natural antivenene prevented death ; and, indeed, so perfectly 

 antagonised this certainly lethal dose that no decided symptoms 

 of poisoning were manifested. In the latter case, 5 cc. per 

 kilogramme was found to be a sufficient quantity to prevent death. 

 I hope by-and-by to extend these observations by testing the 

 antidotal power of this serum against the venom of the actual 

 Hamadryads from whose blood it had been separated. 



A determination of this kind has, however, been made with 

 the blood-serum and venom of the Australian black snake 

 (Pseitdechis porphyriactis), a deadly serpent whose bite pro- 

 duces intense destructive changes, not only at the place where it 

 has been inflicted, but also in the V)lood and in many of the 

 organs of the body. When the blood-serum and the venom of 

 this serpent were mixed together outside of the body, and then 

 injected under the skin of a rabbit, it was found that half a 

 cubic centimetre per kilogramme of the blood-serum was sufficient 

 to prevent death from rather more than the minimum-lethal dose 

 of venom. 



Notwithstanding the obliging co-operation of the India Office, 

 I have not yet succeeded in obtaining the blood-serum of the 

 cobra, but it may safely be anticipated that it also will be found 

 to possess antivenomous properties. 



It has thus been shown that venomous serpents themselves 

 possess a definite substance in the blood-serum which is capable 

 of protecting them against their own venom, and the venom of 

 other serpents. The results of the experiments made by stomach 

 administration of venom, supply at the same time an explana- 

 tion of one, at least, of the methods by which this substance is 

 introduced into the blood. This natural antivenene, however, 

 is apparently not so powerfully antidotal as the antivenene 

 obtained by the process of artificial protection. 



The foregoing statements, although referring mainly to 

 observations on the lower animals, have, probably in every 

 particular, a very direct bearing upon both the prophylaxis and 

 treatment of snake-poisoning in man. 



Some little consideration of the details of the application of 

 ♦.he antivenene and the employment of auxiliary measures may, 

 however, be serviceable ; and, equally of practical service, some 

 consideration of the probable limitations to the capacity of 

 antivenene as an antidote. 



In the meantime, I cannot adduce any actual experience of 

 its use in human beings, as although a considerable quantity, 

 both in the liquid and dry state, was last summer sent to India, 

 and a smaller quantity to Africa, no opportunity for using it as 

 an antidote has as yet occurred in the districts to which it had 

 been sent. 



But, first, let me say in regard to the altogether unsatisfactory 

 experience of the use of medicines, ordinarily so-called, that I 

 am not prepared to take the extreme position that no good 

 can be done by their employment. While the evidence shows 

 that no one of the very large number of those that have been 

 recommended as antidotes is able, in any conditions of adminis- 

 tration, to prevent death after the reception of even the smallest 

 lethal dose of venom, it still may be that, by the physiological 



NO. 1382, VOL. 53] 



effects which they produce, they may assist any efficient antidote, 

 such as antivenene, in preventing death ; and also, by prolong- 

 ing life, increase the opportunity for a more thorough use of 

 this antidote. In this category I would especially place 

 medicines which increase excretion, such as diaphoritics and 

 diuretics ; many of the rapidly acting stimulants of the circula- 

 tion, such as alcohol and the old snake remedy, ammonia ; and 

 stimulants of respiration, such as atropine and strychnine, the 

 latter of which is enthusiastically championed by Dr. A. 

 Mueller, of Sydney. And not only medicines, but also any 

 measures that are available for these purposes, including 

 artificial respiration, so distinctly indicated as a probably 

 valuable therapeutical application in snake-bite by Fayrer and 

 Brunton, which, though shown by the Indian Snake Com- 

 mission to be incapable of preventing death when alone trusted 

 to, was also shown to possess the valuable auxiliary power of 

 prolonging life. 



The first measure, however, that is usually and properly 

 taken in the treatment of snake-bite, is to restrict, as far as 

 possible, the absorption of the venom into the blood-vessels, 

 from the place into which it has been injected by the poison- fangs, 

 by separating this part from the more central parts of the body 

 by a tight ligature. The efficiency of this measure, preventive 

 rather than curative, is fortunately aided by the circumstance 

 that snake-bites are most usually inflicted at parts to which a 

 ligature can conveniently be applied ; for in fifty-four cases col- 

 lected by Wall, the part in nearly 89 per cent, of the cases was 

 on the arms or legs. The ligature having been applied, when- 

 ever it is possible to do so, the next measure to adopt is to open 

 up with a knife, to a considerable depth, the niinute though 

 deep punctures made by the fangs, and then to apply suction to 

 the wound. Justification is found for this procedure in the 

 fact, demonstrated by experiment, that notwithstanding the 

 rapidity with which venom may be absorbed, a portion of it still 

 remains for a considerable time in the tissues immediately sur- 

 rounding the wound. This has been clearly demonstrated by 

 both Kaufmann and Wall. The suction may be produced by the 

 mouth, and in the absence of more effective apparatus this ready 

 method would be serviceable, while it is attended with danger 

 to the operator only in the infrequent occurrence of fissures or 

 abrasions of the mouth. It is, however, more effectively and 

 without any risk accomplished by a suction pump, such as the 

 most useful pump invented by Mr. Andrew Smith, of Cape 

 Colony, which I now show. 



These steps having been taken, antivenene should be injected 

 into the tissues at and near the wound and, also, under the skin 

 above the ligature, and the ligature should not be removed until at 

 least half an hour after a sufficient quantity of antivenene has 

 been injected under the skin above it. 



But the important question has yet to be answered, What is a 

 sufficient quantity ? The whole tenour of my remarks to-night 

 has been to show how necessary it is to bear in mind that there 

 is a definite relationship between the dose of venom received 

 and the dose of antivenene required to antagonise it, and that 

 this relationship also varies with the conditions of the adminis- 

 tration of the antivenene, and, especially, with the interval of 

 time that elapses between the reception of the venom and the 

 administration of the antivenene. 



In snake-bite in man it is impossible to estimate the dose of 

 venom which has been injected, for the nature of the symptoms in 

 the patient cannot give the information even approximately. In 

 searching for a solution of this problem, several facts may be taken 

 into consideration from which assistance may be obtained. And, 

 firstly, what is the probable quantity of venom that a serpent 

 injects into a wound ? Some data for answering this question 

 have, very kindly, been obtained for me by Brigade- Surgeon 

 Lieut. -Colonel Cunningham, of Calcutta. Taking nine adult 

 cobras, healthy and vigorous, he collected from each the venom 

 ejected at a single bite, dried and weighed each collection sepa- 

 rately, and sent me the weights. They are as follows ; — 

 (i) 0726 gramme. j (6) 0-113 gramme. 



(2) 0-262 ,, ; (7) 0-239 



(3) o'ii5 .. i (8) 0306 



(4) 0-144 „ (9) 0-253 



(5) 0-132 „ ; 



The total venoms yield an average of 0*255 gramme for each 

 bite ; hut, if the exceptionally large quantity stated in the first 

 figure be excluded, the average for the remaining eight becomes 

 •195 gramme. It must also be considered that these quantities 



