THE RAPID AGEING AND FIKEPROOFING OF WOOD. L't>3 



or a strip of cloth smeared with rubber, is placed around the base 

 and communicates by means of a tube with a small cask containing 

 an antiseptic solution, which must not be too concentrated. The 

 sap on rising in the tree draws with it the liquid, according to the 

 diameter of the capillary vessels. The tree receives the poison as 

 it receives the nutritive element. In the second case, if the tree 

 is felled, it is placed in a slightly inclined position, and a leather 

 sack, as impermeable as possible, is attached to the trunk and put 

 in communication with a resei-voir 10 or 15 millimetres above.^ 

 The results are quite appreciable, but the pi'ocess is incomplete, 

 the penetration being irregular, and the displacement of the sap 

 almost nil in the heart of the wood. 



In the Renard-Perin process, the piece of wood is sawn at the 

 two ends perpendicularly to its axis. One of the extremities is 

 covered with a sack of impermeable canvas, into which the 

 solution is poured ; the other extremity is connected with a 

 metallic receiver, in which a vacuum is produced by the combus- 

 tion of tow soaked with wood spirit, which completely closes the 

 apparatus. The aspirator draws from the capillary interstices the 

 natural liquids which they contain. These are replaced with 

 the solution under atmospheric pressure. The operation is 

 repeated two or three times. 



In general, the processes by pressure in an enclosure, belonging 

 to the second group, are worked by means of cast-iron cylinders 

 containing the pieces of wood. In many cases a vacuum is 

 produced, at the outset, in the cylinder which contains one or 

 several jjieces ; and the liquid is then introduced under pressure 

 maintained for several hours. 



A modification of the Boucherie and the Renard-Perin processes 

 is the new process of G. Lebioda cfe Co., — the injection of the wood 

 before conversion. The trunk or log is enclosed in a kind of cast- 

 iron autoclave able to support a pressure of 150 atmospheres. The 

 liquid is injected by a 2Jipe under pressure which is gradually 

 increased for a quarter of an hour, in the case of spruce, up to 100 

 atmospheres. The wood is surrounded by the liquid, which is 

 always kept at the same pressure. According to the inventor, the 

 fibres of the wood offer no resistance under this process. The 

 liquid entering, acts like steam, in the Gifford injector. When the 



^ The reservoir is usually fixed some 26 to 30 feet above the timber to be 

 treated. — Hon. En. 



