Trinidad.—Sepe.
In piles of wooden sleepers which have been lying ready for use in India for about six months, at least 10 per cent. have been found destroyed by ants. It has been supposed that the jarring motion of a train on a railway would prevent the white ant from destroying the timber sleepers; but there is reason to doubt this, from the fact that on an examination of the ‘Hindostan’ steam vessel, a considerable portion of her timber framing was found to be eaten away by that destructive insect, particularly in the parts close to the engine and boilers, where there had been the greatest amount of vibration. The telegraph posts are particularly subject to their depredations so long as the timber is sunk in the ground; but when a metallic socket is supplied, the wood is safe from their visits. A further precaution is taken to preserve the lower end of the post by running liquid dammer into the metallic sheath, so that the enclosed part of the post is encased with a coating of resin. The telegraph wires when covered with guttapercha (a vegetable substance) are also liable to their attacks.
Numerous expedients have been suggested for getting rid of this destructive insect, some of which have been successful, but the majority only partially so.
In India, the timbers of a house infested with white ants are periodically beaten to drive them away. Of course, this only succeeds for a short time, as they soon return.
The salt vessels plying on the coast of India use oil of tar, and a considerable quantity of castor-oil, mixed with cow-dung mortar, which, while it adheres to the wood, is an effectual protection against ants and rot. The earth oil, or Arracan oil, is considered as good as creosote to protect wood from ants. It can be obtained at Moulmein and Rangoon, in leathern bottles or skins, at about 6d. per gallon.
It used to be a practice in the West Indies to destroy whole colonies of ants which had built their nests either on trees or under the roofs of houses, by shooting powdered arsenic out of a quill into an orifice made into their covered ways, along which they ascended and descended from and to the ground.
It has been estimated that the depredations of the white ant in India costs the Indian Government 100,000l. a year, which is expended in repairing the woodwork of houses, barracks, bridges, &c.
When Dr. Boucherie gave up his sulphate of copper process for the use of the French public, he received a national reward. If the Indian Government is disposed to give us a national reward, we could show how it may save at least half the 100,000l. a year—which is expended in repairing the damages done by the white ants—with little trouble.
In the Madras Presidency periodical inspections have to be made, not only with regard to the white ant, but with respect to the presence and subsequent germination of vegetable matter or seeds in the mortar. In some instances, where proper precautions had not been taken, roots had formed very rapidly, and of such great size as to bodily dislodge by their pressure large stones from buildings. Therefore, to prevent this germination, a proportion of “Jagherry,” or coarse native sugar, varying from 2 per cent. in ordinary work, to from 5 per cent. to 8 per cent. in arch work, is mixed with the lime.