190 ANIMAL COMPETITORS 
Fumigation is a method of despatch which 
has proven effective with prairie-dogs and 
ground-squirrels, but is of little use in the case 
of gophers or moles, because the latter dig so 
fast and so quickly close their tunnels against 
the fumes as to escape its effects. Machines 
have been invented for blowing the fumes of 
burning sulphur down the burrows. Better 
results, however, are gained with carbon disul- 
phide. This is an antiseptic liquid which may 
be bought in quart-bottles, and is very useful 
in general for killing vermin, protecting stuffed 
birds, etc., in museum cases or in boxes, and 
similar purposes; but must be kept away from 
fire as it is easily inflammable and explosive. 
It evaporates rapidly, making pungent fumes 
in a closed place. The method to be used is 
to carry it, corked, to the mouth of a burrow, 
pour a small quantity upon a little wad of rags 
or corn-husk, or a ball of horse-dung, and push 
it quickly as far as you can down a burrow 
and immediately close the entrance with packed 
earth. Unless the soil is very dry and the bur- 
row extensive the animals at home will be 
smothered. In the case of prairie-dogs, the 
