376 
On Preserving Larch Wood. 
When ^Yoor^ is plunge:! for some time in a strong lime-water solut'on a 
slight petrifiiction of the wood is observable. The carpenter who has to 
work up the wood taken out of tlie lime-water pond, grievously complains 
tlmt the edge of his plane is constantly blunted. This arises from the 
small crystals of carbonate of lime covering the surface of the wood ; and 
also from their having insinuated and crystallized themselves into the 
pores of the wood ; the plane in contact with these has its edge taken off. 
Was thewood prior to being put into the pond smoothed with the plane, 
this objection of the carpenter would be prevented. 
From these few observations upon the late Sir Charles Men- 
teath's treatment of building-timber, it must be apparent that no 
readier, no more economical method of preserving wood has yet 
been discovered. 
In preparing wood for the purposes of ship-building, I think 
it would be well worthy of the attention of the ship-carpenter to 
ascertain by experiments, whether or not his wood, previously well 
steeped in strong lime-water, would not give it ot sea the same 
durability which it is found to have done when so treated in build- 
ings on land. 
Note hy Lord Portman on the Preservation of Fir Timber. 
My experience has proved that Scotch and spruce fir, as well 
as larch, cut when full of sap, and at once plunged in running 
water, and kept therein three months at least, endures twice as 
long as when this plan is not adopted ; and as the timber not so 
treated has perished, while the former is still perfectly sound, in 
buildings where the experiments have been tried, I believe the 
plan to be simple and efficient. The sawyer requires at least 
double pay for sawing the timber treated as I describe. 
Portman. 
