902 16. CROTALIDA 
1.—To prevent as much poison as possible from reaching 
the circulating blood. This resolves itself into: 
a.—Attempts to remove venom from the bitten part by 
sucking or cupping. 
b.—Attempts to destroy venom in the fang punctures 
and in the tissues about them by the injection of chemicals. 
This involves the use of a hypodermic syringe. The chemi- 
cals ordinarily used are one per cent solutions in water of 
either potassium permanganate or chromic acid. 
c.—The stopping of the flow of blood into and from 
the bitten part by means of a tourniquet or tight bandage. 
This, of course, cannot be done if the bite is on the head or 
body. The danger of gangrene resulting from the prolonged 
application of the tourniquet probably has been much over- 
estimated. Dr. William S. Halsted informs me that in his 
surgical service at Johns Hopkins Hospital the blood-flow 
in a limb has been shut off for six hours without gangrene. 
2.—To permit that portion of the venom which cannot 
be removed from the wound, or locally destroyed, to enter 
the circulating blood in small amounts and at safe intervals. 
This must be done by loosening the tourniquet from time to 
time for a few seconds only, regulating the periods of flow 
and the intervals between them according to the severity and 
duration of the symptoms which follow. Unless handled 
in this manner the tourniquet is a source of danger, for its 
sudden removal would permit the blood to carry the poison 
into the general circulation in an overwhelming dose. I have 
seen a frog, into whose leg venom had been injected beyond 
a tourniquet, remain well for 24 hours and then die within 
a few minutes after the protecting band was removed. 
3.—To stimulate and support the vital processes of the 
body as from time to time may be indicated by the symp- 
toms. 
