132 Professor Fraser on Serpents' Venom. [March 20, 



As to the probability, in a fatal snake-bite, of the quantity of 

 venom received by the victim being only about, and not much in 

 excess of, the minimum-lethal dose, it would appear that, in many 

 cases, even so large a dose is not introduced ; for general experience 

 indicates that the majority of persons who are bitten actually recover, 

 whatever treatment is adopted. Sir Joseph Fayrer also shows, in 

 his classical ' Thanatophidia,' that in 64 per cent, of fatal cases of 

 snake-bite in India, the victims survived the infliction of the bite for 

 periods of from three to twenty-four hours ; and this duration of life 

 implies that the dose of venom received could not have been much 

 greater than the minimum-lethal. 



It must be admitted, however, that even for the minimum-lethal 

 dose of venom, the quantity of antivenene required to prevent death 

 in man is probably inconveniently large, especially if, in the treat- 

 ment, reliance is placed solely upon the administration of antivenene, 

 to the exclusion of all or several of the auxiliary measures to which 

 I have referred. It is desirable, also, that the antivenene treatment 

 should be a practical one, not only for doses of venom which do not 

 much exceed the minimum-lethal, but also for the considerably 

 larger doses that are occasionally introduced in snake-bite. 



To attain this object, further work is required in order that 

 there may be obtained an antivenene even more powerful than that 

 whose antidotal capabilities I have described. 



I am not sanguine that this will be accomplished by carrying to 

 a higher degree the process of artificial protection in animals. A 

 comparison of the antivenene of rabbits which had last received 

 thirty times the minimum-lethal dose of cobra venom with that of 

 other rabbits which had last received fifty times that dose, has shown 

 that the latter has but little antidotal advantage over the former, and 

 has suggested that, in the process of artificial protection, the satura- 

 tion point of the blood for antivenene is reached before the possible 

 maximum non-fatal dose of venom has been administered. 



I would anticipate with more hope the results of endeavours to 

 separate the true antivenomous principles from the inert constituents 

 of the blood-serum with which they are mixed ; and although the 

 required chemical manipulations are attended with many difficulties, 

 some success has already been obtained in effecting this separation. 



In the foregoing remarks, it has, however, been showu that even 

 with the antivenene whose properties have been described, human 

 life may be saved in a considerable, if not in a large, proportion of 

 the cases of snake-bite which would otherwise terminate in death. 

 The attainment of this result is a satisfactory one ; for the mortality 

 from snake-bite is large, and is not restricted to the 20,000 deaths 

 which annually occur in India, but includes additional thousands in 

 all the tropical and sub-tropical regions of the world. 



[T. R. F.] 



