244? INDIRECT INJURIES CAUSED BY INSECTS. 



ness that succeeded. So great was their agility that 

 they could seldom be caught or crushed. They were a 

 mute insect, but probably the imago would make noise 

 enough. 



But the white ants, wherever they prevail, are a still 

 worse plague than either of these insects they are the 

 great calamity, as Linne terms them, of both the Indies. 

 When they find their way into houses or warehouses, 

 nothing less hard than metal or glass escapes their 

 ravages. Their favourite food, however, is wood of all 

 kinds, except the teak ( Tectona grandis) and iron-wood 

 (Sideroxylori), which are the only sorts known that they 

 will not touch a ; and so infinite are the multitudes of 

 the assailants, and such is the excellence of their tools, 

 that all the timber-work of a spacious apartment is often 

 destroyed by them in a few nights. Exteriorly, how- 

 ever, every thing appears as if untouched ; for these wary 

 depredators, and this is what constitutes the greatest 

 singularity of their history, carry on all their operations 

 by sap and mine, destroying first the inside of solid sub- 

 stances, and scarcely ever attacking their outside, until 

 first they have concealed it and their operations with a 

 coat of clay. A general similarity runs through the pro- 

 ceedings of the whole tribe ; but the large African spe- 



a It is not its hardness that protects the teak, as the Asiatic Ter- 

 mites attack Lignum Vitae, but probably some essential oil disagree- 

 able to them with which it is impregnated. This is the more likely, 

 since they will eat it when it is old and has been long exposed to the 

 air. Tannin has been conjectured to be the protecting substance, 

 but erroneously, as leather of every kind is devoured by them. Wil- 

 liamson's East India Vade Mecum, ii. 56. It is its hardness probably 

 that protects the iron-wood from the African Termites. Smeathman 

 in Philos. Trans. 1781. 11. 47. 



