ON" PRESERVING TIMBER FROM DECAY. 9 



beet) known that no connexion exists between the tubes laterally ; 

 and this is shewn by the interesting experiment of stopping up or 

 shutting off certain of the sap-tubes at the end of the tree, leaving 

 exposed such as form a word : which word, or name, by the injection 

 of a coloring liquor, can be driven from one end of the tree to the 

 other ; so that wherever the tree is cut through, the name appears 

 distinctly in colored letters on the exposed sections. 



This experiment is interesting, not only in a scientific point of 

 view ; but it shews that none of the processes hitherto used, wherein 

 lateral pressure is involved, can force any preserving liquor into a 

 tree without a degree of violence, which must injure the fibre of the 

 wood, and destroy its strength and use for many purposes. 



The advantages which would result from expelling the sap and re- 

 placing it by an antisceptic fluid, have been long known ; and the 

 idea of effecting this by applying the fluid under pressure at the end 

 of a piece of timber is not new, having been suggested and patented 

 many years ago by Mr. Bethel. But the means then used did not 

 accomplish the object in such a manner as to admit of its commercial 

 application. Hence the more expensive process of creosoting has 

 been adopted ; where the timber is totally immersed in the oil, under 

 pressure, a method which does not permit the sap to escape. 



By the old process of violent pressure, the preserving liquor is 

 forced at right angles to the tubes through the woody fibre of the 

 tree, injuring its strength as well as its capability, in railway sleepers, 

 for example, to resist the wear of the chairs; consuming at the same 

 time an unnecessary amount of the preserving liquor, without (what- 

 ever pressure may be applied) thoroughly impregnating the timber, 

 while one-sixth or one-eighth of the force only is necessary by the 

 new process, and the portion alone requiring the preservative infusion, 

 viz. the soft matter between the rings, is impregnated, the woody fibre 

 remaining unbroken and undisturbed. 



Another important advantage in Dr. Boucherie's process, is derived 

 from the simplicity and moderate cost of the apparatus, which, for 

 operations on a small scale, will not exceed £10 or jSIo, and for a 

 railway of two hundred miles, under £50. 



The practical application and entire success of this invention in 

 Europe will be sees by the primed official reports. The first of these 

 was made, by order of the French Government, in the year 1850, 

 the second in 1852, and the third in 1856 : being an abstract from 

 the official jury report of the Exposition Universelle of 1855, whereby 

 it will be seen that the distinguished honor of one of the large gold 



