VENOMS, TOXINS, ANTIBODIES 343 



It is clear that most, if not all, the above-mentioned properties of 

 venoms are weakened by appropriate irradiation. Noguchi (124) made 

 an extensive study of the photodynamic inactivation of the venoms of 

 the cobra (Naja naia), daboia (Vipera russellii), and rattlesnake {Crotalus 

 adamanteus) . Solutions were made up containing 0.32 or 0.08 per cent 

 (daboia) of dried venom and 0.05 per cent of eosin or erythrosin, and 

 these were allowed to stand in direct sunlight for 30 hr. The hemolytic 

 action of all three venoms was substantially diminished, the effects, 

 according to the author, being greatest on rattlesnake and least on cobra 

 venom. Using "moderate hemolysis" as an end point, cobra venom is 

 most stabile, and daboia and rattlesnake venoms nearly alike; using 

 "no hemolysis" as an end point, cobra and rattlesnake venoms are 

 almost destroyed in the presence of eosin, and daboia venom is least 

 affected, while with erythrosin, cobra venom is unaffected, rattlesnake 

 venom nearly destroyed, and daboia venom intermediate. Noguchi 

 tries to relate these findings to the relative stabilities of the supposed 

 principles neurotoxin, coagulin and hemorrhagin, but all that one can 

 safely conclude is that all the principal toxic effects of these venoms are 

 susceptible of photodynamic inactivation. 



Noguchi also studied the globulin-precipitating and erythrocyte- 

 protecting actions of cobra venom, which he found to be very resistant 

 to photodynamic irradiation. Parallels between thermostability and 

 photostability are suggested. 



Most students of the photolability of venoms have used ultra-violet 

 light. Massol (117) showed that cobra venom (1:10,000) was rapidly 

 inactivated by the light of a 300-watt quartz-mercury-arc lamp; activity 

 was deduced from tests of the lethal effects on white mice. The author 

 also shows, though the data are not very nvmierous, an apparent pro- 

 tective effect of antivenin (immune horse serum) when it is mixed with 

 venom prior to irradiation. No explanation of this is offered. 



Much, Peemoller, and Haim (121) alsoexposed cobra venom (1:2000) 

 to ultra-violet light from a quartz mercury arc, keeping the temperature 

 at about to 2°C. The exposure was equivalent to 72 "skin erythema 

 doses," and the exposed venom completely lost its power to hemolyze 

 human erythrocytes. The authors indulge in much extravagant specu- 

 lation as to the cause and significance of the effects, which they believe 

 to be intimately connected with effects on lipoids, a not improbable 

 assumption. 



One hour of irradiation at 40 cm. from a quartz mercury arc of 

 unspecified characteristics was found by Arthus and Collins to "com- 

 pletely" destroy the in vivo toxicity of daboia and cobra venoms which 

 are primarily coagulative and neurotoxic, respectively. The protective 

 effects of horse serum, egg white, and Witte's peptone when present 

 during irradiation were noted. Similar effects are commonly observed 



