98 Mr. Knight concerning the State in which 
as they do when growing in the best mould. But the water in 
this case, provided that it be perfectly pure, probably affords 
little or no food to the plant, and acts only by dissolving the 
matter prepared and deposited in the preceding year ; and hence 
the root becomes exhausted and spoiled: and Hassenfratz found 
tli at the leaves and flowers and roots of such plants afforded no 
more carbon than lie had proved to exist in bulbous roots of the 
same weight, whose leaves and flowers had never expanded. 
As the leaves and flowers of the hyacinth, in the preceding 
case, derived their matter from the bulb, it appears extremely 
probable that the blossoms of trees receive their nutriment from 
the alburnum, particularly as the blossoms of many species 
precede their leaves : and, as the roots of plants become weak- 
ened and apparently exhausted, when they have afforded nutri- 
ment to a crop of seed, we may suspect that a tree, which has 
borne much fruit in one season, becomes in a similar way 
exhausted, and incapable of affording proper nutriment to a crop 
in the succeeding year. And I am much inclined to believe that 
were the wood of a tree in this state accurately weighed, it 
would be found specifically lighter than that of a similar tree, 
which had not afforded nutriment to fruit or blossoms, in the 
preceding year, or years. 
If it be admitted that the substance which enters into the 
composition of the first leaves in the spring is derived from 
matter which has undergone some previous preparation within 
the plant, ( and I am at a loss to conceive on what grounds this 
can be denied, in bulbous and tuberous rooted plants at least,) 
it must also be admitted that the leaves which are generated in 
the summer derive their substance from a similar source ; and 
this cannot be conceded without a direct admission of the 
