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.coor 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. 0.0001 to 0.00015 gm. per 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 16 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 4o 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 hemolytic 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 
hemolysin of the venom of Lachesis flavoviridis from the hemorrhagin. 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 hemolytic as the original, but its toxicity was 
