JOURNAL 
OF THE 
ASIATIC SOCIETY OF BENGAL. 
Vol. LXIV. Part II.— NATURAL SCIENCE. 
No. III.—1895. 
A contribution to the History of Artificial Immunity .— By Surgeon- 
Lieutenant-Colonel George Ranking, M.D. 
[Read August, 7th.] 
In these modern times when so much advance is beins 1 made in 
medicine, In the direction of the establishment of immunity against 
various toxic principles by the gradual habituation of the system to 
increasing doses of the virus, and then utilising the serum of the blood 
of animals in whom immunity has thus been established, for the “ Vacci¬ 
nation ” as it is conveniently termed of other non-protected animals, in 
many cases with complete success, it is not unworthy of us to enquire 
whether this is a newly discovered principle or whether it is merely a 
revival or development of a principle known to former ages. 
The latest development of the principle of antitoxine immunity is 
the application of the method by which their presence in the serum is 
ensured, to snake poisoning. 
Dr. Fraser of Edinburgh has found a means of so modifying the 
tissues of a non-protected animal, by gradually accustoming the or¬ 
ganism to increasing doses of snake venom, that it not only exhibits 
certain resistance to even fifty times the minimum lethal dose, but also 
that the serum of the blood of these immune animals acquires the pro¬ 
perty of acting as an antidote to the snake poison in other animals. 
To procure this condition of the blood the usual method is to inject 
the venom subcutaneously, but Dr. Fraser has also succeeded in immu¬ 
nising cats by the administration of cobra venom by the stomach, and 
it is this special fact which has led me to the consideration of the 
J. ii. 38 
