122 



§i >ME S<3U i ll INDIAN INSECTS, ETC. 



[CHAP. XI. 



leads a flexible metal pipe. For destroying a m st, a charcoal fire 

 is kindled in the furnace and air pumped through until the fire is 

 thoroughly hot and the metal tube is warmed through by the hot 

 blast driven through the furnace by the pump. The tube is then 

 thrust into one of the main galleries, previouslj opened up, of the 





I Destroying a Termites' Mound with the " Universal 



Exterminator. (Author's original photo.) 



Ant 



nest and a small quantity of a mixture of sulphur and white 

 arsenic is dropped into the furnace, which is immediately closed 

 and the pump worked vigorously. The sulphur and arsenic enter 

 into chemical combination and are expelled from the metal tube as 

 dense yellowish fumes which arc pumped into the nest, any aper- 

 tures by which these an- seen to escape being promptly plugged 

 with wet clay. The pump is worked for ten or fifteen minutes, 

 more sulphur and arsenic being added to the furnace from time to 

 time, and the pipe is then withdrawn and the nest left plugged up. If 

 opened up after an inten a] Oi not less than three days the nest will 

 be found to have been killed off if the fumes have penetrated pro- 

 perly. [f opened up too soon, the effect of the fumes seems to p.iss 



off and the nest may recover, the main effect of the fumes being 



\ isible in the fungus-combs on whose culture the well-being of the 

 colony apparently depends. Care must be taken not to breathe the 

 fumes, as these are poisonous ; but their dense \ ellowish-white COlOUl 

 and noxious odour renders them easily avoided. The exit pipe 

 must be hot before the poison is added or the fumes will condense 

 on its interior surface without penetrating into the nest. 



Another machine, in principle similar to the "Universal 

 Exterminator, is one made in America bj the George L. Squire 

 ( ompanj . In this, however, the current of air is produced by a fan 



