Mr. Knight concerning the State in which 
numerous buds penetrated through the bark in every part, 
many leaves of large size every where appeared, and in the 
autumn every part was covered with very vigorous shoots 
exceeding-, in the aggregate, two feet in length. The number 
of leaves which, in this case, sprang at once from the trunk 
and brandies appeared to me greatly to exceed the whole of 
those, which the tree had born in the three preceding seasons ; 
and I cannot believe that the matter which composed these 
buds and leaves could have been wholly prepared by the feeble 
vegetation and scanty foliage of the preceding year. 
But whether the substance which is found in the alburnum 
of winter-felled trees, and which disappears in part in the 
spring and early part of the summer, be generated in one or 
in several preceding years, there seem to be strong grounds 
of probability, that this substance enters into the composition 
of the leaf : for we have abundant reason to believe that this 
organ is the principal agent of assimilation ; and scarcely any 
thing can be more contrary to every conclusion we should 
draw from analogical reasoning and comparison of the vegetable 
with the animal economy, or in itself more improbable, than 
that the leaf, or any other organ, should singly prepare and 
assimilate immediately from the crude aqueous sap, that matter 
which composes itself. 
It has been contended* that the buds themselves contain 
the nutriment necessary for the minute unfolding leaves : but 
trees possess a power to reproduce their buds, and the matter 
necessary to form these buds must evidently be derived from 
some other source : nor does it appear probable that the young 
leaves very soon enter on this office : for the experiments of 
* Thomson’s Chemistry. 
