NEUROPTERA. 



415 



brmed of agglutinated material, which are stuck along the walls in 

 he cellars and the apartments, or else suspended to the roof like 

 ;talactites. Certain parts of Agen and of Bordeaux begin also to 

 lufifer from the ravages of these insects. The danger appears to be 

 mminent. 



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

 nents on the termites of La Rochelle. Not only has the learned 

 laturalist helped to make known to us the habits of these dark-loving 

 nsects, but he has also told us how to destroy them. Differed 

 ;ubstances have 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 succes- 

 ively binoxide of nitrogen, nitric acid, chlorine and sulphurous acid ; 

 :hlorine, above all, fully answered his hopes. With pure chlorine he 

 :illed the termites instantaneously ; mixed with nine-tenths of air, he 

 luffocated them in half an hour. " For attacking the termites," says 

 Vl. de Quatrefages, " one ought to choose by preference the period of 

 heir reproduction, so as to destroy the pregnant females. It is 

 )robable that, like their exotic congeners, the termites of France will 

 :ndeavour to defend themselves by walling up the interior of their 

 galleries at the first signs of an attack. The operator must then act 

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

 )ossible into the very centre of their habitation, where the galleries 

 ire the broadest and the most numerous. 



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

 >f a first attempt, it seems to me impossible to destroy in one cam- 

 jaign all the termites of a locality. In this, as in all operations of the 

 ame kind, a certain amount of perseverance is necessary, especially 

 f it is in a town or in a country infested by them to a very great 

 legree; in that case one will be forced to repeat the operation from 

 ime to time. When, on the contrary, the termites are already 

 antoned, it seems to me that the success ought to be lasting. This 

 > fortunately the case at La Rochelle ; and by knowing how to profit 

 >y it, one may doubtlessly prevent the spread of these pests, which at 

 ine time or another, may attack the whole town."* 



In 1864 the Lords of the English Admiralty addressed an inquiry 

 D the Entomological Society of London, on the best means of pre- 

 erving wood from the attacks of the Indian termites. In answer to 

 tiis inquiry, the Entomological Society recommended many processes : 



* ' * Memoires sur la destruction des Termites. " Annales des Sciences Naturelles, 

 e serie, tome xx,, p. 15. 



