Of the ant proper, or that belonging to the order Hyrnenoptera, called the carpenter ant, there are three species in particular which attack timber, viz. the Formica fuliginosa, or black carpenter ant; the Formica fusca, or dusky ant; and the Formica flava, or yellow ant.

The first prefers hard and tough wood, whereas the other two prefer soft wood. The carpenter ant, though not very destructive to seasoned wood, has been known to destroy standing timber. Wood, when attacked by the Formica fuliginosa, or black ant, is tinged of a black colour, supposed to arise from iron in its saliva acting on the gallic acid of the timber.

485. One of the most destructive insects to which timber is exposed in tropical climates is the larva of that known as the White Ant, a species of Termite of the genus Termes, belonging to the order Neuroptera. It has very little affinity with the carpenter, or true ant, being a rather disagreeable-looking insect, not quite a quarter of an inch long, having a body about four-fifths of the full length, of a cream colour, very soft and fatty in substance.

It has a head of a dark brown colour, pointed and protected by a thin shell, or hard covering, with two short mandibles.

The body is supported on short dark-coloured legs, which move very rapidly, while the insect itself advances about 2 inches in a second.

The white ant is found both in Africa and the East Indies, as well as in the Mauritius and St. Helena, besides other colonies situated in the Tropics. The African species, T. fatalis, is said to be the most formidable.

According to a well-written paper by Mr. Thomas Houns-low, of the Royal Engineer Department, published in ' Engineering of 21st September, 1866; the white ants will destroy the timber-work of a house, without noise; and frequently, as they never destroy the surface of the wood, without giving the slightest indication of the mischief they are doing. They will eat out the whole of the interior wood, leaving a thin shell of the surface untouched; and in the case of wood that has been frequently painted they will sometimes devour nearly the whole of the wood, leaving only the paint supported here and there by a thin splinter.

The first indication of an attack on the wood-work of a house might be the yielding of a flooring board in the middle of a room, or the top hinge of a door suddenly leaving the frame to which it had been firmly screwed a short time before. In two or three days they will eat a large box full of paper, so as to render it valueless; and at the end of a week they will reduce the whole to a mass of dark-brown dirt.

Teak is said to be almost the only wood the white ants will leave unmolested.* The " Jarrah" timber of Australia is also said to escape their ravages, though they sometimes pierce the sap, or outer wood; but the red timber which constitutes the main body of the tree has not been attacked.

Some experiments were made at St. Helena between the years 1863 and 1866, by order of the Lieutenant-Governor, to ascertain the kind of wood, or the best means of preparing wood, to resist the white ant. Specimens of all kinds of American and European pines, both red, white, and pitch-pine, oak, cedar, ash, elm, beech, birch, mahogany, teak, and a specimen of Jarrah wood from Australia, were placed in situations where they would be most liable to the attack of the ant. Some spesimens of the native pine, or fir of St. Helena, and some of oak, elm, and ash, were chemically prepared - one series, by merely washing over the surface with three or four coats of a poisonous solution prepared from sulphate of copper and chloride of zinc; and another series, by injecting the solution into the pores of the wood, the natural juices having been first thoroughly expelled.

* It is probably some essential oil with which the teak is impregnated that prevents their touching it, as they have been known to eat it when the timber is old and has long been exposed to the air.

Specimens of wood, which had been saturated with corrosive sublimate, chloride of zinc, creosote, salts of lead, and even carbolic acid, were sent from England for trial. At the end of twelve months it was found that the unprepared samples of pine-wood had completely disappeared, and most of the others were reduced to something between a cinder and a sponge in appearance. The Jarrah wood, though attacked severely, was only partially destroyed; but the teak remained in every instance sound and uninjured.

Kaempfer, speaking of the white ants of Japan, gives a remarkable instance of the rapidity with which these insects proceed. Upon rising one morning, he observed that one of their galleries, of the thickness of his little finger, had been formed across his table; and upon a further examination, he found that they had bored a passage of that thickness up one leg of the table, formed a gallery across it, and then pierced down through another leg into the floor; all this was done in the few hours that intervened between his retiring to rest and his rising.*