Relation of the Toxin and Anti- Toxin of Snake- Venom. 93 



venene simultaneously, but separately, under the skin on different sides 

 of the body. These large quantities were introduced by injecting 

 about 2 c.c. into different situations ; 20 c.c. of serum is quite harmless. 



The rectal temperature of each rabbit was taken at the time of 

 injection and each twelve hours subsequently. The fall in temperature 

 caused by the poison is a good indication of the extent to which the 

 animal is affected. 



The conclusions I feel justified in drawing from the above experi- 

 ments are : 



(1) That about the same quantity of anti- venene necessary to 



neutralise the venom in vitro, is capable of doing so when the 

 former is injected into the blood-stream, and the latter sub- 

 cutaneously. 



(2) At least ten to twenty times this quantity is required when they 



are both placed simultaneously under the skin, but in different 

 parts of the body. 



That the proportion of toxin to anti-toxin necessary to neutralise 

 the former should be approximately the same whether they be (1) 

 mixed in a glass, or (2) the anti-toxin be injected into the blood-stream 

 and the toxin subcutaneously, might be expected if the nature of the 

 antagonism between them be a chemical one, and in consideration of 

 the evidence adduced by Kanthack,* Erhlichj Fraser,J Stevens, and 

 Meyer, and Cherry and my self, || I do not see that one can come to 

 any other conclusion. 



The toxin and anti-toxin of snake-poison neutralise one another 

 when mixed together in adequate proportions, quite irrespective of 

 the actual quantity of each. Solutions of the two can be titrated 

 against each other just like standard solutions with the life of a rabbit 

 as an indicator, in which the error in the determination of the " end- 

 point " is one fatal dose. 



If anti-venene be introduced into the blood-stream the anti-toxin is 

 there ready to neutralise the toxin as it is absorbed, and, as might have 

 been predicted, the amount found necessary by titration outside the 

 body is just about adequate to neutralise the toxin as it makes its 

 appearance in the blood. The experiments indicate, however, that a 

 slightly larger proportion of anti-toxin is necessary under these cir- 

 cumstances, for the rabbits 9, 10, 11 lived a little longer than rabbits 

 15, 16, 17. This result may very well be due to delayed chemical 

 action due to the dilution of the anti-toxin in the blood. 



* Quoted by Stevens and Meyer, 'Path. Soc. Lond. Proc.,' March 1, 1898. 

 f ' Fortschr. der Mod.,' 1897, No. 2. 

 J Loc. cit. 



S ' Path. Soc. Proc.,' March 1, 1898. 

 11 Loc. cit. 

 VOL. LXIV. H 



