

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, 
&e. 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. “ 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 femaies. It is probable that, lke 
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 1s 
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 
% “Mémoires sur la destruction des Termites,” Annales des Sciences Naturelles, 
3¢ serie, tome xx., p. 1d. . 

