FOOD OF PLANTS. 
15 
now and then moistened. The growth and verdure were speedily assisted ; and 
the plant flowered well in the late summer : upon attempting to remove the pot, 
it was found to be firmly fixed ; the roots having penetrated and passed through 
the moss, and fastened themselves to the tile, on which they branched most 
extensively. Little or no moisture could be discerned on the tile, nor had the 
roots extended beyond the limits of the moss ; but, under it, they were 
astonishingly numerous, and adhered as firmly to the tile as does ivy to a wall. 
Does not this circumstance tend, among many others, to throw some light upon 
the fact that cuttings emit roots more freely when they are placed against the sides 
of a pot ; and that water alone is sufficient to furnish nutritive food to a variety 
of plants ? 
FOOD OF PLANTS. 
The food of animals always consists either of other animals, or vegetables, or 
a mixture of both, together with water, or some fluid containing a considerable 
proportion of water, for drink ; that is, as a solvent to the more solid matters. 
Plants again, strictly speaking, subsist on drink alone, being indeed incapable of 
taking up any solid matter, at least till it be previously dissolved or diffused 
in water. 
There is an obvious and well-known proof that plants live on water chiefly, if 
not altogether, derived from hyacinths and other bulbs placed in glasses, and sup- 
plied with water, in which they blow as well as in a garden. It is found, however, 
that they do not thrive unless the water is regularly changed, indicating that it is 
not the water alone, but something in the water, which becomes exhausted and 
deteriorated by the feculent slime discharged by the plant. It has also been found 
by experiment, that distilled water will not support a healthy growth in plants ; and 
most, if not all species, when planted in pure calcined sand, and watered with dis- 
tilled water, quickly die, as they do when quite deprived of water. 
From chemical analysis and experiment, it appears that the chief matters taken 
up by plants, besides water, consist of carbonic acid gas and azote, together with a 
few salts, such as potass ; and out of these, and the hydrogen and oxygen of the 
water, all vegetable products seem to be wholly or chiefly elaborated. 
M. Lassaigne proved that these all pass into the plant from without, by the 
ingenious experiment of analysing the chemical constituents of seeds before and 
after germination. 
When by chemical experiment substances are found in plants different from 
those supposed to have been introduced from the soil, it is not to be inferred that 
the plants have created these, but that they have gradually taken them up in very 
minute portions, till a considerable quantity has been produced. 
It is proper to confess, however, that we are still much in the dark upon this 
interesting subject, it being extremely difficult, if not impossible, to trace the 
fluid taken up by a plant after it passes beyond the ^uxisiCQ.— -Alphabet of Botany. 
