17,1 Monserrat et al.: Philippine Cobra Venom 61 
0.00035 gram. Lamb gives 0.00025 gram as the intravenous 
lethal dose for monkeys. 
Comparing our figures with those arrived at by other workers, 
it seems that the venom of Naja philippinensis is considerably 
more toxic for the lower animals than those studied elsewhere. 
For man the lethal dose of Indian cobra venom was estimated 
by Lamb at from 0.015 gram to 0.0175 gram, for a person of 
from 60 to 70 kilograms of body weight, his conclusions having 
been based on his experiments with monkeys. 
Assuming the resistance of man to cobra venom to be inter- 
mediate between that of the monkey and the rabbit, we can 
estimate the minimum lethal dose of the Philippine venom to 
be about 0.00019 gram per kilogram of body weight, or from 
0.0095 gram to 0.0114 gram for a person weighing from 50 to 
60 kilograms, the approximate average weight of Filipinos. 
Therefore, the amount of venom a single alupong possesses, 
which is estimated to be 0.052 gram, would suffice to kill five 
persons of 50 kilograms weight. 
Il. SYMPTOMS OF COBRA VENOM INTOXICATION 
The symptoms generally observed in the experimental animals 
are as follows: Twitching of the lids, ears, and sometimes of 
the muscles of the body; excessive salivation, nausea, and vomit- 
ing; loss of voice, rapid respiration, and drop in temperature. 
We also observed lacrymation and a very marked ptosis of the 
upper eyelids, especially in monkeys. 
From the very beginning there is great weakness. Emission 
of semen and involuntary defecation take place immediately 
before death. Death is caused by the cessation of respiration 
first, while the circulation is affected later. 
Ill. HEMOLYTIC PROPERTIES OF THE VENOM 
Though the toxicity of the venom of our Naja has been found 
to be somewhat higher than that of the other species of the 
same genus, its hemolytic power according to our observations 
is slightly lower. 
The venom of Naja philippinensis, like that of Naja 
tripudiams, can hemolyze washed red corpuscles of man, dog, 
rabbit, and guinea pig, but cannot hemolyze the erythrocytes 
of sheep, goat, and cow. These differences are, of course, only 
quantitative. 
The activating power of blood sera of certain vertebrates for 
the hemolysins contained in the Philippine venom is analogous 
to that described in the case of Naja tripudians, except that 
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