262 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 
unheated venom solutions did. Heating of the immune serum to 55°C. 
for 30 minutes did not affect its precipitating quality and quantity. The 
reaction appeared with the dilutions down to o.cor per cent, but not with 
0.0001 per cent. 
The precipitin tests made with the venoms of Bungarus fasciatus, Notechis 
scutatus, and Echis carinata were all negative, namely, no precipitate was 
formed with these venoms. 
The above experiments of Lamb clearly point out that the proteids of two 
entirely different snake venoms, both from the physiological and zoological 
standpoints, can eventually be identical; hence these proteids can have no 
relation to the real toxic components of these venoms. While a venom of a 
colubrine snake (cobra) and that of a viperine snake (daboia) may have 
similar proteids, it does not follow that all viperine venoms are similar in 
this regard. On the other hand, Lamb found that the venoms of two colubrine 
snakes (Bungarus fasciatus and Notechis scutatus) did not contain any pro- 
teids which could react with the cobra anti-serum. Echis carinaia, a viper, 
also has no corresponding proteids with those existing in the venoms of cobra 
and daboia. 
In a subsequent communication Lamb!’ extended the precipitin test to 
various venoms representing practically the entire class of Ophidia. The 
immune serum used as the precipitin was prepared in rabbit by repeated 
injections of pure unheated cobra venom. With this cobra anti-serum he 
obtained the following results: 
COLUBRID: COLUBRID: 
Elapine : : Hydrophine : 
Naja tripudians = + Enhydrina valakadien 
bungarus ° 
Bungarus ceruleus o 
fasciatus o 
Notechis scutatus 0 
VIPERIDE: VIPERIDE : 
Viperine : Crotaline : 
Vipera russellii + Lachesis gramineus 
Echis carinata oo Crotalus adamanteus o 
+ = strong reaction. X = weak reaction. — = no reaction. 
From the foregoing table it becomes evident that the precipitin-reaction 
bears no relation to the zoological classification of snake, but is of the most 
irregular nature. Neither does it seem to have any relation to the physiologi- 
cal or toxicological constitution of the snake venom. 
Lamb also brought out the fact that the antitoxic value of antivenin has no 
relation to the precipitin content of the serum. Three antivenins of high 
strength have been found to possess almost no precipitating property. He 
sought the reason for this non-occurrence of precipitation in the species of 
the animals, holding that asses and horses are unsuitable for the precipitin 
production. 

1Lamb. On the precipitin of cobra venom. Lancet, 1904, II, 916. 
