"be meant of such as are in a state of vegetation," &c.

Now plants, it is well known, respire similarly to animals, through the
pores of their leaves. By the agency of the sun, during the day, a
quantity of pure gas, called oxygen, is given out; but on the contrary,
during the night, or absence of the sun, gas of a most noxious and
pernicious nature is emitted, and at the same time a portion of the pure
air (oxygen gas) is absorbed. The greater part of the atmosphere must
therefore be impregnated with this deleterious gas. Taking into
consideration the confined state of a bed-chamber, the great increase of
perspiration of the body, with the continual increase of carbonic gas
from respiration, and this in an apartment where every thing _ought_
most sedulously to be avoided which in the least tends to deteriorate the
atmosphere, it must be evident the practice ought to be avoided, if we
are desirous of preserving health.

Flowers in a state of vegetation are, I consider, more pernicious _at
night_, or during the absence of the sun, than those plucked and put
into water, provided they be not immersed too long a time; for
immediately the stem is severed from the plant, the vital action, if it
may be so termed, ceases, and decomposition commences; but till the
decomposition has been going on some time, nothing of a pernicious nature
need be apprehended. In like manner, directly the vital principle becomes
extinct in animals, decomposition ensues. For the space of five or six
days, however, no perceptible alteration of the fibres is visible; but
after that time a compound of gases begins to exhale from the body,
accompanied with a fetid odour, till the parts are entirely decomposed.

The effluvium arising from the _farina_ and _petals_ is
considered unwholesome, however agreeable it may be to the senses,