THE PRESERVING OF TIMBER FOR ESTATE PURPOSES. 79 
having the wood submitted to the preserving process as soon as 
possible after it is cut off the root. When this is not done, or the 
timber is Otherwise seasoned, decomposition of the albumen and 
other matter in the cells is liable to produce carbonic acid, which 
shows itself in the fir tribe in the decay known as “ bluewood.” 
As the sap of most broad-leaved trees contains a certain quantity 
of astringent matter, it rather tends to preservation than decay, if 
the wood, while seasoning, is slightly protected from the weather. 
This is especially the case if the wood is cut down in winter. 
‘‘Bluewood” is scarcely known to exist in this class of timber. 
Therefore any process by which the soluble matter in the cells can 
be coagulated, without diminishing the strength of the tissue,. may 
be adapted with great advantage. That is done chiefly by im- 
pregnating the cells with certain salts or oils. 
Various methods of impregnating timber with antiseptic 
substances, with the object of preserving it from decay, have 
been adopted at different times. Of these, Sir William Burnett's 
—immersion in a solution of chloride of zinc; Mr Kyan’s— 
immersion in a solution of corrosive sublimate; Mr Margery’s— 
a solution of sulphate of copper, applied under pressure; Mr 
Paine’s —a solution of sulphuret of barium or calcium, combined 
with a solution of sulphate of iron, injected successively into the 
wood ; and Mr Bethell’s—the use of heavy oil of tar, commonly 
termed ‘‘ Creosote,” injected into the wood—have been the most 
widely used during the last fifty years. Forsome time Mr Kyan’s 
process was the one commonly adopted, and to such an extent was 
it used that all systems of preserving timber for constructive 
purposes were popularly termed ‘ Kyanizing,” 
particular process employed. 
irrespective of the 
Experience, however, showed that the use of metallic salts was 
not successful in timber exposed to the action of water, as they 
were dissolved and washed out of the wood, leaving it unprotected, 
aud the processes in which these salts were used are now seldom 
employed in Britain, except as a preventative of dry-rot in 
buildings, where the smell of creosote would be objectionable. 
For all other purposes ‘‘ Creosoting” is practically the only method 
now in use in this country. 
At the same time, timber impregnated with salts, such as sulphate 
of copper, chloride of zinc, or other antiseptics, may be used with 
decided advantage in those structures which are protected, by 
painting, roofs, or otherwise. In the construction of farm- 
