474 Proceedings of Royal Society of EcUnhurgh. [skss. 
Althougli the quantity of dry serum was small, there was 
sufficient to allow three experiments to he made, for the purpose of 
determining if it can prevent death from being produced by a lethal 
dose of venom, when the two are mixed together before 
administration. In one of these experiments, the dose of serum 
was 1 C.C., and that of venom *0035 gramme per kilogramme of 
animal ; in the second, the dose of serum was *5 c.c., and the dose 
of venom the same as in the first experiment ; and in the third 
experiment, the dose of serum was 1 c.c., and that of venom *004 
gramme per kilogramme of animal. In each case, the gratifying 
result was obtained that the animal survived the administration 
of these lethal doses of venom. 
It has thus been shown that venomous serpents themselves 
possess a definite substance in the blood-serum, which possesses 
antidotal properties against their OAvn venom and the venom of 
other species of serpents. 
It is probable that the substance is produced from venom shed 
upon the mouth-surface, and absorbed into the blood from this 
surface or elsewhere in the alimentary canal, and also from venom 
absorbed directly into the lymphatics and blood-vessels of the 
poison-glands. At the same time, the protection which is enjoyed 
by several species of serpents may also be produced by venom 
introduced into the body with the venomous snakes on which some 
of them, and especially the Hamadryas, largely subsist. 
The blood - serums of the two species of venomous serpents 
that have been examined are certainly not so powerfully antivenene 
as the serum which can be obtained from artificially protected 
animals. They have, however, been obtained in conditions which 
are not the most favourable for determining the true value of the 
blood-serum of serpents. This can probably only be done in the 
countries in which the serpents are found. 
If this natural antivenene be found to be powerful, then a new, 
and in some respects convenient, source for antivenene will become 
available ; but even if the antidotal power be not so great as that of 
the serum of artificially protected animals, it is possible that its value 
may be increased, and a sufficiently powerful antidote obtained, 
more rapidly than with entirely unprotected animals, by injecting 
several successive doses of venom into the serpents themselves. 
