IMMUNITY 



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neutralizes the venom of Vipera russellii and Crotahis durissus, but 

 has no action upon — -Colubridae : Naja tripudians Merrem, A^. hun- 

 garus Schleg., Bungarus candidus h., B. fasciatus Schn., Enhydrina 

 valakadien Boie; Viperidse: Echis carinatus Schn., Lachesis gramineus 

 Shaw. 



3. TidswelVs Pure Noteckis scutatus Ptrs. Serum. — 'This serum 

 has a strong antitoxic effect upon the venom of Notechis scutatus, 

 but hasno effect upon that of — Colubridae: Naja tripudians Merrem, 

 N. bungarus Schleg., Bungarus candidus L., B. fasciatus Schn., 

 Enhydrina valakadien Boie; Viperidae: Vipera russellii Shaw, Echis 

 carinatus Schn., Lachesis gramineus Shaw, Crotalus durissus L. 



4. Noguchi's Pure Crotalus Serum. — It has a strong effect upon 

 Crotalus venom, and a slight effect upon Ancistrodon piscivorus 

 Lacep., and none on the cobra. 



5. Noguchi's Pure Ancistrodon piscivorus Lacep. Serum. — ^This has 

 a marked effect upon moccasin-venom, and medium effect upon 

 Crotalus, and none on cobra-venom. 



6. Brazil's Pure Crotahis horridus L. Serum. — -This semm is 

 equally ef&cient for the venoms of Crotalus horridus or C. durissus, 

 but is useless for cobra- venom. 



The Caracas Commission reports that this serum is more effica- 

 cious against the venom of Crotalus than that of Calmette, which 

 fails to neutralize the hsemorrhagins. 



7. Kitajima's Piire Lachesis flavoviridis Hallow Serum. — 'This 

 serum is specific for Lachesis venom, against which Calmette's 

 serum is useless. 



It is clear that the antisera mentioned above are very nearly 

 specific, for they neutralize principally the venom of the species 

 employed, and sometimes, in larger doses, that of some allied 

 species. 



It is obvious that this is of great importance in considering the 

 serum treatment of snake-bite. 



* 8. Polyvalent Sera. — Polyvalent sera prepared for more than two 

 venoms are not very efficacious. 



Diagnosis. 



It might be thought that the diagnosis of snake-bite would be 

 obvious, and that nothing need be written on the subject, but this 

 is not always so, because snake-bite often takes place in the dark, 

 and the nature of the snake is unknown. 



The diagnosis may be divided into two heads:— (i) Has a snake 

 bitten the person ? (2) Was the snake a poisonous one ? 



The first thing to do is to tie a proximal ligature on the limo, 

 and then to examine the area of the supposed bite. If there are 

 absolutely no fang-marks and no venom on the skin, then obviously 

 there is no danger; but fang-marks on the skin, or venom on mucous 

 membranes (which, of course, may have cracks), or on skin with 

 scratches, may be dangerous. 



If there are no fang-marks, and the snake is forthcoming, examine 



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