NEUROTOXINS OF SNAKE VENOM 147 



when in solution. The addition of sodium hydrate to the watery solution 

 of ophiotoxin soon renders it inactive. Unless slight acidity of the solution 

 is maintained by metaphosphoric acid it becomes totally or partially inactive 

 during evaporation. The resistance to heat is not stated, but it appears to 

 be very sensitive, as 40 C. affects its strength. 



The injection of 0.000085 to o.oooi gm. per kilo body- weight of ophiotoxin 

 into a rabbit causes no appreciable symptoms during 15 to 20 minutes, but 

 afterwards it shows diminished respiration and languidness. The locomotive 

 faculty is gradually troubled, paralysis first attacking the hind legs and quickly 

 extending to the front legs. Dyspnoea and paralysis of the body and legs pro- 

 gress and after 45 to 60 minutes cessation of respiration ensues. The heart 

 beats for some time after this stage is reached. The symptoms produced by 

 intravenous injection are the same as the above. In dog the intravenous 

 injection of ophiotoxin causes about the same symptoms as in rabbit, but the 

 peripheral paralysis is not so pronounced, o.oooi to 0.00015 8 m - P er kilo of 

 the body-weight is a minimal dose for dog, when injected intravenously, death 

 ensuing in 45 to 50 minutes. 



In frog, when 0.05 mg. of ophiotoxin is introduced into vena abdominalis 

 it becomes completely paralyzed in 10 minutes, but death takes place after 

 12 to 1 6 hours. With this animal it can be shown that there is, besides the 

 central, also the peripheral paralysis. The irritability of muscles to electric 

 stimuli is not affected in this case. 



Subcutaneous administration of ophiotoxin is much less toxic and it requires 

 3 mg. for rabbit and 6 mg. for dog per kilo body-weight to get fatal effects, 

 namely, 30 to 40 times larger than the minimal lethal dose by intravenous 

 injection. 



The administration of ophiotoxin per os causes only insignificant symptoms, 

 salivation, nausea, vomiting, and diarrhoea being observed in dog, but only 

 slight diarrhoea in rabbit. 



Concerning the action of ophiotoxin upon the blood, Faust found that it 

 has a moderate haemolytic power. Noteworthy is his finding that ophiotoxin 

 attacks the blood corpuscles without the aid of serum or lecithin, whereas the 

 native cobra venom requires these substances for complete haemolytic process 

 with the corpuscles of ox, goats, or sheep. 



Faust thinks it probable that ophiotoxin exists in the venom as an ester- 

 like compound of albumose or peptone, and that in that state it is more stable 

 and more easily absorbed from the tissues. 



The action of antivenin upon ophiotoxin has not been mentioned. 



Ishizaka employed another method for separating the neurotoxin and 

 haemolysin of the venom of Lachesis flavoviridis from the haemorrhagin. He 

 shook the venom solution with chloroform for 10 minutes and then the pre- 

 cipitate was removed by centrifugalization. The supernatant fluid was again 

 treated with chloroform and separated from the coagula. This process was 

 repeated several times in succession and he obtained a clear solution. This 

 fluid was still as strongly haemolytic as the original, but its toxicity was 



