2 2 Fur7iiiure Beetles. 



the solution may be used instead of the tetrachloride by itself. 

 The naphthalene remains as a deposit in the wood for a long 

 time after the liquid has evaporated, and serves as a protection to 

 it, though it adds to its inflammability, and may on that account 

 be objectionable. 



One of the oldest and most effective methods of treating 

 worm-eaten wood is to inject it with a solution of corrosive 

 sublimate (mercuric chloride) in methylated spirits. But, owing 

 to its extremely poisonous nature, mercuric chloride is a very 

 dangerous substance to use for the purpose, though with reason- 

 able care it might be used on a small scale and in special cases. 

 To be really effective in destroying the worm, it would need to be 

 used in the proportion at least of five parts to one hundred of the 

 liquid. As a protection to wood against the worm a one or two 

 per cent, solution would probably suftice. In 1864, a commission 

 appointed by the Science and Art Department to inquire, recom- 

 mended fumigation with benzene vapour as the most suitable 

 method for destroying the worm in wood-carvings and other kinds 

 of woodwork preserved in the South Kensington Museum ; and as 

 a future protection from the attacks of the worm, they advised 

 painting with a solution of mercuric chloride in methylated spirits 

 or in parchment size, according to the nature of the surface to be 

 treated, the proportion in either case to be sixty grains of the 

 chloride to each pint of the liquid used, or somewhat less than a 

 one per cent, solution. In the process known as the Kyanizing 

 of wood, it is saturated under pressure, or injected, with a one to- 

 three per cent, solution of corrosive sublimate in order to protect 

 it from the decay due to either fungi or insects. The disease of 

 timber called dry-rot is brought about by the attack of fungi, and 

 is not to be confounded with the powdered state which results- 

 from the action of the worm. Dry-rot and the worm are, however, 

 very often found closely associated in the same wood, the damp,, 

 ill-ventilated conditions which conduce to the one being also 

 favourable to the development of the other. 



In cases where discoloration of the wood does not matter, as- 

 in outbuildings, and in the structural wood of dweUing-houses, it 

 may be treated with carbolic acid, creosote, or one of the other 

 tar-oil derivatives, as a protection from the worm as well as from 

 other sources of decay. 



Best time to apply treatment to worm-eaten furni- 

 ture. — Prom what has been said of the life-history of the beetles, 

 it will be understood that the larvae or worms approach the surface 



