SEASONING AND IMPREaNATION OF TIMBEE 279 
to have invariably failed, as indeed have all the salts of 
metals. The North Eastern Eailway Company always 
paint the kyanized timberwork to prevent the salts being 
washed out. This process is a good deal used on the 
Continent for small timbers such as posts, stakes for grape 
vines, etc., but as the corrosive is very poisonous care has 
to be taken in the handling. Timber preserved by this 
process has a life of seventeen years in Germany. 
Powellized Wood was the treatment of wood by a strong 
solution of sugar, invented in Great Britain a few years 
ago. 
Salt is an excellent preservative for timber, and in the 
days of the old wooden ships a layer of salt between the 
inner and outer planking secured a year's longer classing 
at Lloyd's ; it is recommended by the American Lloyd's 
and still required by the Lake underwriters for new first- 
class vessels. 
Creosoting, which is the system of timber preservation 
best known and mostly used in Great Britain, was the 
invention of Mr. John Bethell in 1838, the same year 
which saw the invention of burnettizing, and these two 
may be said to be the only systems which are still largely 
used. 
Creosoting is hy far the best preservative for tiniher. It is 
good in all situations and in all conditions, and even those 
who largely use the zinc chloride and other processes are 
unanimous in giving the first place to creosoting, and are 
only deterred from using it because of its much greater 
cost, or because it is unsuitable for the situation where the 
timber is to be used, such as interior work. 
By this process distilled coal tar is injected under 
pressure into timber (properly seasoned to allow the 
