SNAKE TOXINES. 223 



The action of snake venoms upon the blood was subsequently 

 more closely studied by FLEXNER and NoGUCHi. 1 



For this purpose they used the venoms of Naja tripudians, 

 Crotalus adamanteus (rattlesnake), Ancistrodon piscivor.us (mo- 

 cassin snake), and Ancistrodon contortrix, all of which only 

 showed slight differences. 



The action of these was tried upon the blood of the dog, 

 rabbit, guinea-pig, sheep, ox, pig, necturus, and frog. The blood- 

 corpuscles were washed before the experiment, and then only 

 simple agglutination without haemolysis took place. The blood 

 of the rabbit was the most susceptible to this influence, and then 

 that of the guinea-pig, dog, sheep, pig, and ox. 



The amount of haemolysis to be observed in defibrinated 

 blood stood in no constant relationship to the agglutination of 

 the washed blood-corpuscles. The separate action of the 

 haemolysis and agglutination could be observed at C., since 

 the latter was not affected by the temperature. 



Cobra venom was the strongest hsemolytic agent, and rattle- 

 snake venom the weakest. Dogs' blood was the most susceptible, 

 and ox blood the least, leaving out of the question frogs' blood, 

 which was almost completely refractory. 



The haemolysines are very resistant to the influence of heat. 

 They were not affected at all by temperatures of 70 to 80 C., 

 and were only slightly injured even after fifteen minutes at 

 100 C. In this respect they resemble the heat-resisting bac- 

 terial lysines ; the agglutinines, however, are destroyed in thirty 

 minutes at 75 to 80 C. The haemolysine can also withstand a 

 temperature of 100 C. for thirty minutes. On the other hand, 

 the lysine is destroyed by the same chemical agents as the toxic 

 components (KYES and SACHS, vide infra). 



The hsemolytic principle is absolutely distinct from the true 

 nerve poison. A solution of the poison that has been freed from 

 toxine by treatment with brain substance still retains all its lytic 

 properties, and is therefore still poisonous. But if it is then 

 subjected to further treatment with blood-corpuscles, it is, in the 

 case of cobra venom, which contains hardly any haemorrhagine, 

 rendered almost completely innocuous. In immunisation, how- 

 ever, both an ti toxine and antilysine are formed, so that anti- 

 snake venom serum also prevents haemolysis. 



Haemolysis occurs only in the presence of fresh serum, and this 

 has been shown by PmsALix 2 to be also the case with the 



1 Flexner and Noguchi, " Snake Venom in Relation to Haemolysis," 

 Journ. ofExper. Med., vi., 277, 1902 (reprint). 



2 Phisalix, "Action du venin de vipere, &c.," Soc. BioL, liv., No. 27, 1902. 



