Oil the Use of Homc-groim Timber. 
211 
" They, therefore, are justly regarded as the primary cause of 
the decay in timber. Soaking; in water, especially in running 
water, to some extent removes from wood soluble albuminous 
matters, and in some measure improves the condition of timber 
by rendering it more capable to resist decay than otherwise. In 
practice, however, it has been found that immersion in common 
water does not satisfactorily remove the injurious albuminous 
compounds, which by their subsecpient decomposition on ex- 
posure to air cause the gradual decay of timber. 
" Lime, like corrosive sublimate, precipitates albuminous 
matters, and renders them inactive. Hence it is largely em- 
ployed by sugar-boilers, for the purpose of removing such 
matters from the juice of sugar cane. For the same reason it 
appears to me well adapted to neutralise and render inactive the 
soluble albuminous matters in timber, and thereby to protect it 
against decay. I may mention further that wood immersed for 
some days in lime-water takes up lime, in the shape of a perfect 
solution, as caustic lime. On subsequent exposure of the wood 
to the air, the excess of lime which remains in the wood after the 
precipitation of the albuminous compounds gradually absorbs 
carbonic acid, and the woody fibre throughout the whole mass of 
the wood becomes coated with insoluble carbonate of lime. To 
some extent the interstices of the timber become filled with 
carbonate of lime, and the wood to some extent is mineralised, 
which strikes me is an additional recommendation of the lime 
process of protecting timber against decay." 
Such is the chemical view of the question. 
I will now give you the result of mechanical test, with a view 
to show how far the impregnation of the wood with carbonate of 
lime hardens and strengthens it, or the reverse. Upon this point 
I have consulted Mr. David Kirkaldy, the value of whose expe- 
riments upon the strength of materials is well known. The 
following figures represent the result of the experiments he has 
recently made to ascertain the resistance to a pulling strain and 
a thrusting stress of four pieces of wood marked A, and four 
marked B. 
Pulling Stress. 
A, 
B. 
Stre.ss in lbs. per 
stress in lbs. per 
No. 
Square Inch. 
No. 
Square Inch. 
lbs. 
lbs. 
1 
G381 
1 
8961 
2 
5896 
2 
7782 
3 
5788 
3 
7302 
4 
4437 
4 
6441 
Miiian 
.. 5(;2fi 
Mean 
.. 7622 
p 2 
