of the alhurnous Vessels of Trees. 303 
spring, and the return of a large portion of this matter to 
the roots would probably be prevented : * the timber I have, 
however, very little doubt would be much improved by 
standing a second year, and being then felled in the autumn ; 
but some loss would be sustained owing to the slow growth 
of the trees in the second summer. The alburnum of other 
trees might probably be rendered more solid and durable by 
the same process ; but the descending sap of these, being of 
a more fluid consistence than that of the resinous tribe, would 
escape through the decorticated space into the roots in much 
larger quantity. 
It may be suspected that the increased solidity of the wood, 
in the fir-tree I have described was confined to the part 
adjacent to the decorticated space ; but it has been long known 
to gardeners, that taking off a portion of bark round the 
branch of a fruit-tree occasions the production of much blos- 
som on every part of that branch in the succeeding season. 
The blossom in this case probably owes its existence to a 
stagnation of the true sap extending to the extremities of the 
branch above the decorticated space ; and it may therefore be 
expected that the alburnous matter of the trunk and branches 
of a resinous tree will be rendered more solid by a similar 
operation. 
• The roots of trees, though of much less diameter than their trunks and 
branches, probably contain much more alburnum and bark, because they are wholly 
without heart wood, and extend to a much greater length than the branches ; and 
thence it may be suspected that when fir-trees are felled, their roots contain at least 
as much resinous matter, in a fluid moveable state, as their trunks and branches ; 
though not so much as is contained, in a concrete state, in the heart wood of 
those. 
R r 
MDCCCVI. 
