128 Professor Thomas B. Fraser [March 20, 



produces intoxicating effects in man, evidences of which have been ob- 

 served in many of the experiments made by me on the lower animals. 



The results of the experiments in which the venom was introduced 

 into the stomach, probably also afford an explanation 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 prac- 

 tised by them, and protection 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 con- 

 taining 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 antivenomous pro- 

 perties. 



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

 last year obtained from India several living specimens of the Hama- 

 dryad (Ophiojphagus elaps), a serpent of greater size and more aggres- 

 sive 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 c.c. per kilo- 

 gramme 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 c.c. 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 (Pseudechis 

 jiorphyriacus), a deadly serpent whose bite produces intense destruc- 

 tive changes, not only at the place where it has been inflicted, but 

 also in the blood and in many of the organs of the body. AVhen 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. 



