In 1856, in consequence of the ravages of the white ants in the King’s Magazine, Fort William, India, the flooring and powder racks had to be reinstated. Captain A. Fraser, R.E., had the basement covered with concrete, 4 lb. of yellow arsenic being added to every 100 cubic feet of concrete. In the mortar used for the pillars arsenic was used in the proportion of ½ lb. to every 100 cubic feet of brickwork; a small quantity of arsenic was also mixed with the paint, and ½ lb. (four chittacks) of arsenic was also mixed with every 100 superficial feet of plaster. In 1859 the town mayor reported to the Government that no traces of white ants had since been found either inside or outside the building.
Colonel Scott, when Acting Chief Engineer, Madras Presidency, reported to the Government, December 24, 1858, that the following receipt was used for exterminating white ants in the Madras Presidency, and was found to be very successful:
| lb. | oz. | ||
|---|---|---|---|
| Arsenic | 2 | 4 | |
| Aloes | 2 | 4 | |
| Chunam soap | 2 | 13 | (common country soap). |
| Dhobies mud | 2 | 8 | (Khar). |
Pound the arsenic and aloes, scrape the soap, mix with mud, and boil in a large chatty half full of water until it bubbles; let it cool, and when cold, fill up with cold water. The mixture should boil for nearly an hour: it is applied as a wash.
The white ants of Calcutta are small in comparison with those of the upper provinces.
Colonel Scott, Chief Engineer at Bombay, records instances of timber being boiled under pressure in various antiseptic solutions, such as sulphate of copper, arsenious acid, and corrosive sublimate, with satisfactory results; but considerable apparatus is necessary, and the expense forbids its use except in large public works. On the other hand, in 1847, Mr. G. Jackson, being engaged under Mr. Rendel, C.E., on works in India, tried several experiments with Mr. J. Bourne, in order to test the possibility of preserving timber from the ravages of the white ant. Ninety pieces of wood, 9 inches long by 4 inches square, saturated according to the different processes of Burnet, Payne, and Margary,[31] under the direction of the patentees themselves, were experimented upon, in five situations, one with a considerable amount of moisture, and four dry; through inadvertency Mr. Bethell’s specimens were only tested in the dry positions. The result was, that where there was moisture the timber was entirely destroyed, whilst where they were kept dry the result was better, but still not satisfactory. It seems difficult to account for these different results obtained by Colonel Scott and Mr. Jackson; but evidently the same strength of solutions, and the same qualities and descriptions of woods, cannot have been used by each gentleman.
Captain Mann and Captain McPherson painted the joists and planking of several buildings at Singapore with gambir composition, and the result was perfect success, although the buildings had been previously infested with white ants. Gutta gambir is juice extracted from the leaves of a plant of the same name (Uncaria gambir) growing in Sumatra, &c., inspissated by decoction, strained, suffered to cool and harden, and then cut into cakes of different sizes, or formed into balls. Chief places of manufacture, Siak, Malacca, and Bittany; gambir is now imported to England to a slight extent. The gambir composition referred to is made as follows: Dissolve three pints of gambir in twelve pints of dammer-oil over a slow fire; then stir one part of lime, sprinkling it over the top to prevent its coagulating and settling in a mass at the bottom; it must be well and quickly stirred. It should then be taken out of the cauldron, and ground down like paint on a muller till it is smooth, and afterwards returned to the pot and heated. A little oil should be added to make it tractable, and the composition can then be laid over the material. To be treated with a common brush. Against the Teredo navalis may be substituted the same proportion of black varnish or tar for dammer-oil, of course omitting the grinding down, which would not answer with tar.
Burnett’s chloride of zinc process is said to be a good preservative for wood liable to be attacked by ants: the zinc penetrates to the heart of the wood.
Creosoted timber, it is well known, resists the attacks of the white ants; but the close grain of the generality of tropical timber renders any attempt to creosote it all but useless. Of course, creosoted fir timber could be, in fact is, exported from England, but the cost of freight and other charges will always make it very expensive, and be a great drawback to its general use abroad. Mr. J. C. Mellis, Engineer to the Government of St. Helena, writes in very high terms of creosoted timber as used there, where the white ant abounds. Between the years 1863 and 1866, experiments[32] were made with many specimens of woods (by order of the Lieutenant-Governor), in order to find out those which would resist the white ant. Teak remained uninjured; jarrah wood was partially destroyed; while pitch-pine, oak, cedar, ash, elm, birch, beech, and mahogany, were quite destroyed.