putrefaction 
Vital air, or orygen gas, the other constituent part 
cessary to make up for the great consumption 
by respiration and combustion. 
sential dependence of 
e 
he 
be nara, airy It is of all vegetable 
matter.—[See Note 2d, on range 
be truly esteemed individual 
uds 0 
‘nina and, if one of them be planted in the earth, 
with a cup Saivertnd over it, to FEO fo eo 
from being at first greater than its p 
it will produce a tree similar to its Saat Tt tiny 
sometimes be necessary, to prevent the bud from bleed- 
ing to death, to close the wound caused by the abscis- 
sion, with a cemen 
Linnzeus Shockiven: that trees and shrubs are roots 
above ground; for, if a tree be inverted, leaves will 
grow from the root part, pty roots from the trunk part. 
Buds and bulbs are all annual productions, termed, 
by Linnzeus, the hybernacula, or winter cradles of th 
plant. And Darwin observes, that the same term might 
properly be applied to seeds also 
te h bud has a leaf, which is its lungs, appropriated 
ne absorb carbonic acid gas, or fixed air, by their 
upper surface, _ give out a fie gas, or pure respira- 
ble air, by their as first discovered by 
Dr. Priestly. 
Dr. Ingenhousz improved upon this discovery, by 
observing light to be necessary to these functions; ro- 
marking that in the dark, leaves give out a beds & 
carbonic air, and that fruits and flowers almost invaria- 
bly give out the last mentioned kind of air, at all times, 
but <A E in the dark. 
udes to this noxious quality in his tenth 
Diba 
« But haste 
The shades are found— 
Ev’n Juniper’s sweet shade, whose leaves around 
Fragrance diffuse, at eve are noxious fou 
Homeward, ye well fed Goats, now smd ‘the day, 
3, glittering comes! my Goats away!” 
It has long been known tha gh 
upon the upper surface of leav 
acts beneficially 
to the light, or forcibly kept in such an un 
tion, the leaves grow sickly, black, or discolored; as 
may be seen in plants trained against a wall. 
ves, if separated from their parent branch, 
and suspended by a slender thread, will turn their upper 
surface to the light, and vary their position, as the sun 
pag his course. Bella ies leaves are an excep- 
tion ; have no upper under surface, but are 
cst “a do not alter he position. 
Light is considered as a stimulus or agent which de- 
composes the various nutritive principles, to be found 
in the air and water. It seems, in many instances, to 
be the sole cause of the expansion of flowers and leaves; 
for when it is bereodt tes fold together and droop 
as if dying; this egantly termed by Linnzus, 
‘‘the sleep of the Fs ee oe the Mimosa pudica, or 
sensitive plant, is a beautiful example of it. This plant, 
if kept in a dark room, for a considerable time, will re- 
quire several minutes’ exposure to the solar light before 
the stimulus bu the light will dispose it to unfold, or ex- 
pand its lea 
Leaves avave turn towards the light; this is neces- 
sary to the formation of their color, as may be seen by 
the common practice of blanching res — &e., 
by covering them from the light; 
Edinburgh, gives an account of a slant found in the 
drain coal-work under ground, which was very 
luxuriant, with large indented foliage, and 
white. He had not seen any thing like it, nor ‘doaid 
had 
in a little time the leaves wi 
leaves began to to spring up, of @ green color, and of a 
different shape from that of the old ones. rolling 
one of the leaves between his finzers, he ‘Gand that it 
had the of common Tansy, and it ultimately 
