96 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 
Light does not have a deteriorating effect on dried venom, but a marked 
reduction of toxicity is observed when the solution of venom is exposed to 
the direct sunlight or diffuse daylight during many days. The alteration is 
more marked with the venom of cobra than with the crotalus, and is quicker 
at 37° C. than at a lower temperature. The nature of this modification of 
toxicity will later be discussed in fuller detail. 
The action of certain fluorescent aniline dyes upon the venom was studied 
by Noguchi, who found that the chief toxic principles of cobra venom — 
namely, neurotoxin and hematoxin — are more stable than the hemorrhagic 
principle of crotalus venom. Besides the deadly principle of daboia venom a 
fibrin ferment is easily destroyed by eosin or erythrosin in the direct sunlight. 
Phisalix passed a continuous electric current through the venom solution 
and found that the latter becomes destroyed. He attributes this to the 
formation of a sufficient quantity of chlorated products (chlorates, hydro- 
chlorites, etc.) and ozone from the salts accompanying the venom. An alter- 
nating current of high frequency applied to the venom solution, with the view 
of producing a vaccine, is said to have produced vaccinating substance, but 
Marmier found that if the rise of temperature be avoided by appropriate 
apparatus no modification of venom results. 
Phisalix found that the emanation of radium attenuates and then destroys 
the virulence of cobra venom and viper venom. With cobra venom he 
observed precipitation of proteins and subsequent loss of toxicity. With the 
venom of the viper he found that the chloroform-water solution of the venom 
in 1 : 1000 when exposed to the radium ray gradually becomes attenuated 
until its action completely disappears. 
A series of tubes were exposed to the radium, the first for 6 hours, the 
second 20 hours, and the third 36 hours. The control unexposed venom 
solution killed a guinea-pig in ro hours; the first exposed venom in 12 hours; 
the second in 20 hours, and the third produced no symptom. A second inocu- 
lation to the last animal caused a fall of o.5° of temperature temporarily. 
After 4 days, a single minimal lethal dose killed the animal. The solvent of 
venom exerts a great influence on the effect of radium emanation. If the » 
venom is dissolved in 50 per cent glycerin water the attenuation is still slight 
after 6 hours’ exposure to radium. 
EFFECTS OF VARIOUS CHEMICALS. 
The attempt of various investigators to discover an agent which destroys 
the venom in the tissue or in the organism with the least or no injury 
to the latter has achieved no great success. However, the results of the 
researches in this direction have contributed much to our chemical knowl- 
edge of venom, and some of the latest chemical studies have had the 
advantage of these chemical stabilities of venom against various chemical 
substances. In the following pages the results obtained by various investi- 
gators will be given. 
