126 Professor Thomas B. Fraser [March 20, 



introduced into the stomach. 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 immunity against only certain lethal doses of venom, and, 

 for each lethal dose caj)able 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, nevertheless 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 antiveuene, and not venom, was introduced 

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

 sions relating to the production of immunisation against 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 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 antivenomous, 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 administration 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 



