190 ANIMAL COMPETITOES 



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 furnes 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 



