ANTIBACTERICIDAL PROPERTIES OF SNAKE VENOM 217 
From this it may be concluded that the specimen of venom employed by 
Flexner and Noguchi destroyed the bactericidal properties of dog serum 
against B. typhosus when added in the proportion of 0.00005 gm. of venom 
to 1 c.c. of serum, and that 0.00002 gm. in the same quantity of serum 
was practically without action. 
Flexner and Noguchi found that o.coor to 0.0006 gm. of copperhead 
venom added to 1 c.c. of Necturus serum removed only a part of its bacteri- 
cidal properties against B. coli and B. typhosus, but its inaction was very 
remarkable in contrast to the other serums they employed. It may be 
remarked that Necturus is highly refractory to venom. An animal weighing 
250 gm. received without ill effect 0.05 gm. venom, equivalent to 160 mini- 
mal lethal doses for the guinea-pig of equal weight. 
The effect of heat upon venom in relation to its action upon the bactericidal 
properties is of interest. For this purpose cobra, water-moccasin, copperhead, 
and rattlesnake venoms were studied. Temperatures varying from 75° to 
go® C. were employed, and the heated venoms were mixed with the stream- 
ing blood in Nuttall bulbs and with the separated serum. ‘The venom was 
kept at the lower temperature (75° C.) for 30 minutes and at the higher 
temperature (90° C.) for 15 minutes. The heated venom acts just as the 
unheated, except in the case of crotalus venom, the effect of which is some- 
what diminished at the higher temperature (90° C.). 
Finally, Flexner and Noguchi attributed the antibactericidal properties of 
various venoms to the fixation or inactivation of bacteriolytic complements, 
but not to any perceptible alterations on the part of intermediary bodies 
(amboceptors) of these serums. 
In 1905 Noc! made interesting observations concerning the anticomple- 
mentary property of cobra venom. He found that the bacteriolytic actions 
of the fresh serums of the rabbit, horse, guinea-pig, rat, and man are com- 
pletely annihilated by this venom, which is due to the fixation of comple- 
ments by venom. He employed hemolytic reaction to demonstrate the 
absence of complements from the venomized serum. Normal rat serum is 
hemolytic upon the corpuscles of horse blood, and this was used as the test 
reaction. He prepared 6 different combinations: 
TABLE 19. 
) Normal rat serum o.5 c.c. 
) Normal rat serum 0.5 c.c.+0.0005 gm. cobra venom, after 15 min. i c.c. antivenin. 
Normal rat serum 0.5 c.c.+0.001 gm. cobra venom, after 15 min. 2 C.c. antivenin. 
Then 2 drops of defibrinated horse blood were introduced into each tube 
and incubated at 37°C. 
The results: Complete hemolysis in a few minutes in (1) and (6). In (4) 
hemolysis completed in 1 hour, but no hemolysis in (2) and (3), showing 
that o.5 and o.cor gm. of cobra venom completely destroyed alexine in 15 

1Noc. Ann. Inst. Pasteur, 1905, XIX, 209. 
