128 Inverted Action of the alburnous Vessels of Trees. 
matter to the roots would probably be prevented *: the tim- 
ber I have, however, very little doubt would be much im- 
proved 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 fiuid 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 
blossom on every part of that branch in the succeeding sea- 
son. The’blossom in this case probably owes its existence 
to a stagnation of the true sap éxtending 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. +, ' 
I send you two specimens of the fir wood I have described, 
the one having been taken off above, and the other below 
the decorticated space. The bark of the latter kind scarcely 
exceeded one-tenth of a line in thickness; the cause of which 
I propose to endeavour to explain in a future communica- 
tion relative to the reproduction of bark, 
Iam, &c. 
T. A. Knieut. 
* 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 net so muchas is contained, ina concrete 
state, in the heart woed of those. ; 
