422 
ON CHEMISTRY. 
Light as applied to vegetable bodies imbued with life, is produc¬ 
tive of manifest effects; but it is a mistake to suppose that there can 
be a state of total seclusion from its influence. It is usual to say 
that plants, in a dark cellar are void of colour ; and, certainly in such 
a situation, they retain little, if any of the green tint of a healthy 
growth, exposed to the direct ray; but air is replete with light,— 
this is provable by direct experiment; water abounds with light, and 
enough may be extracted by vital action, to secure a weak existence, 
and even some colour. Nothing can he more completely buried in 
apparent obscurity than the roots of a plant in a pot of mould ; but 
let any one take out the ball of a vine, of an Enythrina laurifolia, 
&c. &c. and he will soon perceive that the terminal points of the ad¬ 
vancing roots are tipped with a pea green tint. A Rhubarb plant 
growing in a dark corner of a cellar has gorgeous colours—almost a 
golden yellow, relieved with lively red, yet in a few hours these tints 
will yield to green, if the plant be removed to air and daylight. 
But another manifestation of one of the chemical energies of light, is 
at hand in all vegetable progress, and that is electricity. Hence it 
is, doubtless, that plants increase most rapidly when atmospheric 
changes, productive of warm showers, are most active. I speak how¬ 
ever of the silent electricity which results from the decomposition of 
aerial water, and of manuring (that is, nutritive) substances within 
the range of the rootlets of plants. Electricity in masses, produced 
by our machines, as it has been artificially employed, possesses no¬ 
thing in common with the silent influence exerted by the passage of 
atmospheric electricity, inducing a corresponding action about the 
roots. The one is unnatural, a violent passage of a shock, or at least, 
of a luminous stream, wholly at variance with the secret energy of 
native electricity, and destructive of vitality : the other is a gentle, 
invisible medium, suitable in every sense to the capacity and want 
of the being which it stimulates. The whole process of nutrition 
depends, I conceive, upon this electrizing principle of solar light, and 
that will be considered in a future paper. All that now remains to 
be adduced in corroboration of this hypothesis of vegetable life, (inde¬ 
pendently of the phenomenon of the dew, of which mention was made 
in the last paper) is the fact to which I beg the reader to bend his 
whole powers of reflection. Vegetables are either acted upon, stimu¬ 
lated, and,impelled, to the performance of all their vital functions ; 
and if this he fact—then what is the stimulant ? Or they are beings 
imbued with life, and having the power of volition, perception and 
discrimination! Where is the alternative P i\Iy own opinion, 
after mature consideration, is this—that plants are mere instruments, 
