o 
} 
Mitchell repeatedly pointed out the danger of secondary bacterial in- 
fection in victims surviving the primary effects of snake poisoning and 
W. H. Welch, in 1893, discovered that rattlesnake venom causes blood to 
lose its bactericidal power. Normal blood serum destroys thousands of 
bacteria, while venomized serum does not possess this power, 
Some knowledge of the action of crotaline venoms is of greatest im— 
portance to American physicians, as 99 percent of the cases of snake bite 
treated in the United States are caused by pit vipers. At the present time 
extensive experimental use is being made of the venoms of the cobra, vipers, 
and crotaline snakes in the alleviation of the pain accompanying malignant 
growths such as cancer and in the treatment of arthritis. One of the great 
possibilities of the use of venoms in medicine undoubtedly lics in the 
ability of certain of the venoms to accelerate coagulation of haemophilic 
blood. 
MORTALITY RESULTING FROM SNAKE BITE 
The average mortality from bites of the American venomous snakes was 
estimated by Wilson in 1908 as little more than 190 percent of those bitten, 
but with modern methods of treatment fatalities have been reduced to less 
than 4 percent. <A study carried on by the Antivenin Institute of America 
(1927) has shown, however, that the danger from snake bite has been under- 
estimated. It was found that in the course of one year (July 1926 to 
June 1927) in Texas something like 150 cases wore reported. Of these, anti- 
venin was given in 83 cases, with 78 recoveries and 5 deaths, the death rate 
being 6 percént. The death incidence was higher than would have been the 
case had the antivenin been administered sooner. In the remaining 67 Cases, 
in which the antivenin was not injected, 23 died, the death rate being 34.3 
percent. In the Northeastesrn States it has been estimated that the mortal— 
ity rate, in the absence of special treatment, is ‘10 to 1S percent of “bhose 
bitten, the increase bcing largely due to the copperhead. In Georgia, 
Florida, and Alabama, the average mortality is 18 to 25 percent. In Texas, 
New Mexico and Arizona, the death rate is somewhat higher, no doubt because 
of the presence of the westcrn diamondback rattler (Crotalus atrox) and 
ranges from 25 to 35 percent of those bitten. Estimates ranging from 100 
to 1,500 cases in the United States each year of persons bitten by veno— 
mous snakes show the present’uncertainty that exists in regard to the 
prevalence of accidents of this sort, 
The tendency of rattlesnakes to rattle whenever disturbed and to 
continue the rattling as long as the disturbing influence is present also 
explains why victims are not more numerous. The timber rattler has been 
known to keep up its rattle for half an hour with but few intermittent 
momentary pauses. The fact that the water moccasin lives in unfrequented 
swamps and the harlequin snakes have burrowing habits end small-sized mouths 
account for the infrequency of bites attributed to these species. 
In fatal cascs the time intervening between the bite and death varies 
greatly, Cases termineting fatally within a few minutes do occur, though 
fortunately they are very rare. There is a record (Roberts) that a boy 
7 years old bitten by a rattlesnake on the cheek below the eye pitched 
forward dead before an cye witness could reach him. A little girl 3 years 
old bitten on the forehead by a large rattlesnake died within 10 minutes 
=) ye 
\ 
