THE TECHNOLOGIST. [May 1, 1865. 



454 ON THE RAVAGES OF ANTS. 



localities, however, on the coast of France, a very small species has 

 proved extremely destructive to wooden structures, so much so as to 

 cause very serious apprehensions ; and Myrniica domestica, an exotic 

 species accidentally introduced, has occasionally taken possession of 

 houses at Paris. 



In James Town, St. Helena, the white ant has prevailed to an ex- 

 tent seldom heard of in countries abounding with that scourge. It 

 appears to have been introduced into the islandabout twentyyears ago, but 

 it is only within the last ten years that its ravages have increased to 

 such an extent as to make some attempt at extirpation a matter of 

 necessity. Churches, schools, offices, and dwelling-houses of both rich 

 and poor have been equally attacked. Goods in warehouses of various 

 kinds are destroyed continually. The Customs' House is invaded — 

 wine casks are destroyed ; the corks of wine, beer, and spirit bottles 

 eaten out; books, clothing, and furniture in dwelling-houses are 

 nowhere safe, and the loss to the inhabitants of the island is of an 

 immense amount, and the expense continually incurred is enormous. 



Under such circumstances it was obvious that full inquiry ought to 

 be made as to the most probable means of prevention, and the kinds of 

 wood most likely to escape. For this purpose information was obtained 

 from various quarters by ihe standing committee, and amongst others 

 Sir W. J. Hooker sent specimens of various woods most likely to resist 

 the plague. All the softer woods, as might be expected, more or less 

 rapidly fell a sacrifice ; or if, from some accidental or unknown circum- 

 stance, some particular piece had escaped for years, when removed to 

 another situation it was quickly destroyed. Teak seems less subject to 

 attack than other woods, and in the course of the experiments Myrtaceas 

 seem in general to have resisted better than woods belonging to other 

 natural orders, though some, as the Blue Gum {Eucalyptus globulus), 

 perished. A few hard Brazilian woods also escaped, together with some 

 other kinds, as Mammea, Hymencea Courbaril, and Cedrela odorata. 

 In some cases, where specimens were not attacked at first, they did not 

 endure a longer trial. 



It was hoped that the processes which have been adopted with a 

 view to prevent dry rot, as those of Sir W. Burnett, Jackson, Kyau, &c, 

 might either prove destructive to the insects from the large quantity of 

 poisonous metallic salts with which the wood was impregnated, or, at 

 least, be distasteful ; but in general complete impregnation proved no 

 less inefficacious than partial coating. Sulphate of copper, chloride of 

 zinc, sugar of lead, arsenic, corrosive sublimate, carbolic acid, and 

 creosote, all in turn proved useless, and in some cases the destruction 

 was total. Mr. Langton's charring process was not more successful. 

 One of the most hopeful appears to be a process suggested by Lieut.- 

 Colonel Baker, late Garrison Engineer at Lahore, which consisted of 

 rosin and earth oil rubbed into charred wood while hot. Col. Baker 

 recommended also, but less successfully, sulphate of copper, in the pro- 



