When once this disease has set in, the cure is very difficult, as the whole place where the timber is situated becomes infected. Measures should be immediately taken to provide proper ventilation, and to cut off the access of moisture; the diseased parts of the timber should be cut away, and every particle of fungus removed by brushing the walls and adjoining timbers; after which a wash should be applied to all infected places, consisting of some solution that will destroy any germs of fungi that may lave escaped the brush.

Sir H. Davy proposed corrosive sublimate, which should not be of less strength than 1 ounce to every gallon of water, aid on hot. A solution of sulphate of copper, in the proportion of about

8 ounces to a gallon of water, is said to make an excellent wash, and is cheaper than the corrosive sublimate.

A mixture of sulphate of copper and sulphuric acid in the proportion of 1 lb. of each to 6 gallons of water has been found to preserve timber for nearly double the ordinary period. The sulphate of copper should first be dissolved in gallon of boiling water, and the remainder of the water d sulphuric acid added afterwards.* Sulphate of iron has been used as a wash for timber, but is not so efficacious as sulphate of copper. Oil of tar also makes an excellent wash for timber that is infected with the dry rot, hut the smell is very much against its use in situations that are inhabited.

* Brown's 'Forester,' 4th edit., 1871.

When a mere antiseptic is required, probably one of the best that can he used is carbolic acid in its crude state. The surface of the timber and the place on which it rests should be washed over with it; but, like oil of tar, the smell is objectionable in some situations.

504. To prevent the attacks of the Sea-worm, the most effectual remedy is to thoroughly impregnate the wood with creosote. Nails closely driven over the surface of piles below high water, when carefully performed, have been found to protect them from the attack of these animals. This and covering the surface with sheet copper, are perhaps the only methods known of resisting the attack of the Limnoria terebrans.

505. The only timber that will resist the White Ants is Teak (Tectona grandis) and Iron wood (Sideroxylon). The Jarrah wood of Australia sometimes escapes their ravages, but all other woods are attacked by them. The only effectual remedy has been creosote; but even that if it has not penetrated the wood thoroughly will not avail.

Corrosive sublimate, chloride of zinc, salts of lead, even creosote and carbolic acid, have all been tried at St. Helena with no more effect than to retard the destruction of the wood for a few months.

For the true ant, or Formica, arsenic has been used in the West Indies; and Thunberg has found cajeput oil effectual in destroying the red ants of Batavia: he used it to preserve his boxes of specimens from them. When ants were placed in a box anointed with this oil, they died in a few minutes.*

* Thunberg's ' Travels,' vol. ii., p. 300.