620 The American Naturalist. [July, 
PHYSIOLOGY. 
Attenuation of Viper Poison.—Ina commnnication published 
in Revue Scientifique Feb., 1894, M. M. C. Phisalix and C. Bertrand 
published the results of experiments made with the venom of vipers.. 
Fresh venom from Vipera aspis extracted from the glands rapidly 
loses its virulence when subjected to a temperature of 75°-80°, and an 
aqueous solution so treated exhibits energetic innoculating properties 
against the venom itself. 
They have also demonstrated that the blood of animals innoculated 
with this echidno-venin becomes antitoxic, the injection of this defi- 
brinated blood or of the serum into the peritoneal cavity of healthy 
guinea-pigs, neutralized the effects of the venom. 
They add that the blood of guinea-pigs protected by a poison habit, 
that is, by injections of pure venom in increasing quantities, adminis- 
tered at gradually decreasing intervals, is also antitoxic, but to a 
less degree than that of animals protected by vaccination. Animals 
protected by innoculation with antitoxic serum preserve their immu- 
nity quite a long time. 
heir observations are such as lead them to believe that this anti- 
toxic serum will prove to be a therapeutic agent. 
. Since then, M. Calmette, who had questioned the correctness of the 
results of their experiments, but who later retracted his assertions, has 
presented a note in which he annnounces “that one can protect ani- 
mals against the venom of serpents by means of repeated doses of 
poison, at first weak, but gradually increasing in strength ..... and 
that the serum of the animals thus treated is at once protective, anti- 
toxic and therapeutic.” This is precisely what M. M. Phisalix and 
Bertrand demonstrated; but M. Calmette, not having cited their 
researches, they think they should lay claim to priority in publishing 
the important theoretical and practical consequences of this discovery, 
having been able to give in logical sequence the facts upon which the 
results are scientifically established. (Revue Sci., May, 1894). 
The Secretion of Urea.—It is well known that urea exists 
already formed in the blood when it reaches the kidneys, and that so 
far as this substance is concerned, the kidneys function as eliminating 
organs. But in what part of the organism then is the blood charged 
m with the urea? The researches of M. Kaufman, who has been at work 
