20 Furniture Beetles. 



be applied without some risk of grave consequences to the furni- 

 ture as well. 



1. Treatment by heat, wherever it can safely be applied, 

 is undoubtedly one of the quickest and most effective methods of 

 destroying the worm in worm-eaten wood or furniture. The heat 

 need only be sufficient to raise the wood in its deeper parts to a 

 temperature of about 55° 0. ( = 131° P.), and is generally best 

 applied in the form of dry heat. Unless the wood were more 

 than a few inches in depth, this temperature in the interior would 

 be attained by subjecting it for an hour or two to a heat not 

 exceeding that of boiling water or steam, 100° C. (= 212° F.). 

 Articles of a conveniently small size may be heated in a gas oven, 

 the temperature of which can be regulated so as not to exceed the 

 required amount. Small flat articles could be sufficiently heated 

 over a hot-water cistern. In the case of large articles, a hot-air 

 jacket or hot-air chamber may be necessary. 



2. Fumigation with a gas or vapour. — A gas can penetrate 

 more deeply than a Jiquid into wood, and is, therefore, more 

 likely to reach and destroy the larvae in the deeper parts. Fumi- 

 gation, however, depends greatly for its success on the degree to 

 which the chamber or other receptacle in which it is carried out 

 can be made airtight. Specially constructed chambers or large 

 cylinders, from which the air can be pumped out and replaced 

 with the fumigating gas or vapour are of course best ; but in their 

 absence use can be made of such means as are available, a large 

 tightly-fitting box, a glass case, a tank, a small spare room, etc. 



The most effective gas to use for the purpose, hydrocyanic 

 acid gas, is at the same time the most dangerous. It is a deadly, 

 poison, and should never be used for the treatment of furniture 

 except by experts who are familiar with the danger and will take 

 all the necessary precaution in carrying out the measures required. 



The heavy vapour given off from carbon disulphide on exposure 

 to the air is nearly as effective, and on the whole is less dangerous ; 

 but it takes fire at a not very high temperature, and if mixed with 

 air is liable to explode with violence. It must therefore be used 

 only with very great caution. The method is the same as in the 

 case of benzene vapour mentioned below, but the dishes into which 

 the liquid is poured should rest on a bracket or shelf fitted near 

 the top of the fumigating box or other receptacle instead of being 

 placed at the bottom. 



Sulphur dioxide, the gas or vapour generated by burning 

 sulphur, has certain disadvantages owing to its tarnishing and 



