NEUROPTERA. 415 



We are indebted to M. de Quatrefages for some interesting ex- 

 periments on the termites of La Rochelle. Not only has the 

 learned naturalist helped to make known to us the habits of 

 these dark-loving insects, but he has also told us how to destroy 

 them. Different substances had been tried in vain to stop these 

 terrible ravages essence of turpentine, arsenical soap, boiling lye, 

 &c. M. de Quatrefages had recourse to gaseous injections. He 

 tried successively bioxide of azote, nitric acid, chlorine and sul- 

 phuric acid, chlorine above all fully answered his hopes. With 

 pure chlorine, he killed the termites instantaneously ; mixed with 

 nine- tenths of air, he suffocated them in half an hour. a For 

 attacking the termites," says M. de Quatrefages, "one ought 

 to choose by preference the period of their reproduction, so 

 as to destroy the pregnant females. It is probable that, like 

 their exotic congeners, the termites of France will endeavour to 

 defend themselves by walling up the interior of their galleries at 

 the first signs of an attack. The operator must then act with a 

 great deal of promptitude, and direct the apparatus as much as 

 possible into the very centre of their habitation, where the galleries 

 are the broadest and the most numerous. 



" With whatever care one acts, and whatever may be the success 

 of a first attempt, it seems to me impossible to destroy in one 

 campaign all the termites of a locality. In this, as in all opera- 

 tions of the same kind, a certain amount of perseverance is 

 necessary, especially if it is in a town or in a country infested by 

 them to a very great degree ; in that case, one will be forced to 

 repeat the operation from time to time. When, on the contrary, 

 the termites are already cantoned, it seems to me that the success 

 ought to be lasting. This is fortunately the case at La Rochelle, 

 and by knowing how to profit by it, one may doubtless prevent 

 the spread of these pests, which, at one time or another, may attack 

 the whole town."* 



In 1864, the Lords of the English Admiralty addressed an in- 

 quiry to the Entomological Society of London, on the best means 

 of preserving wood from the attacks of the Indian termites. In 

 answer to this inquiry, the Entomological Society recommended 



* "Memoires sur la destruction des Termites," Annales des Sciences Naturettes, 

 3 e serie, tome xx., p. 15. 



