268 
H. C. YARROW. 
the snake was chloroformed, and if this is done the reptile gen¬ 
erally succumbs within a few days. This fact is mentioned as it 
has been learned through the public prints that some experimenters 
in a neighboring city have succeeded in squeezing out the venom 
while the snake was active. 
The quantity of venom obtained from different individuals 
varies greatly. From a large rattler weighing perhaps three or 
four pounds, our first attempt resulted in securing about fifteen 
drops of venom after the reptile had struck three times; but if 
the process is repeated every day or two but a very small quantity 
is obtained. The smallei; snakes give a much smaller quantity. 
The cotton after having received its charge of venom was removed 
from the stick and washed out carefully in glycerine, and by 
measuring the quantity of this substance first, and then after the 
venom had been added, we were able to tell accurately the 
strength of the solution, which consisted of eight drams of chem¬ 
ically pure glycerine and one dram of the venom. This is the 
preparation which was used in all the experiments, and is called 
glycerine-venom. One fact should be stated as bearing upon 
the popular belief that snakes, if kept from water, are not poison¬ 
ous. It was found that by keeping the rattlers without water for 
a week or two the quantity of venom was materially smaller 
than when we allowed them free access to water, and that the 
color of the venom, which was yellowish-green when no fluid was 
supplied, became much lighter in color when they had freely 
drunken. We have never been able to induce our rattlesnakes to 
eat, although they have been tempted with a variety of food, but 
water they consume largely. 
When the present supply of rattlers was first received, it was 
a very easy matter to grasp any one of them behind the neck 
with the snake staff; but experience has taught them that they 
must do something against their will, and now it is quite difficult 
to secure them, and even when secured it is difficult to make them 
strike ; in fact, one specimen is now so tame that it may be handled 
with impunity, and it is the writer’s belief that a rattler, if care¬ 
fully and tenderly handled, will not bite the hand that grasps it. 
It is believed the Moqui Indians are aware of this, and it enables 
