another beneficial effect of the glass in
excluding the quantity of sooty particles
deposited on its surface, which would otherwise
have fallen on the leaves, and interfered with
the process of respiration for which they are.
specially designed. We shall also observe that
the glass is covered within, on the colder side,
with globules of moisture, and these tell us of
another beneficial influence which it exerts.
One difficulty experienced in growing plants
in London under the old method, consisted in
the dry character of the atmosphere of towns,
compared with that of the country, and the
consequent trouble in keeping plants
sufficiently watered. If the mould be well
saturated with water, this will rise in vapour,
the escape of which is prevented by the glass.
It consequently becomes condensed on its
cold surface, streams down the side, and thus
alternately rises and falls, little or no escape
taking place, and many months, or even years,
elapsing before a fresh supply is required.

Again, the glass covering, though so closely
fitted as to exclude soot and dust, and prevent
the escape of the watery vapour, is not
intended to be air-tight or hermetically sealed.
If it were, the glass would be broken by the
first expansion or contraction of the air
contained within, which takes place with every
rise and fall of temperature, and by which, to
some extent, the change of atmosphere necessary
for the well-being of the plants is effected.
This is further ensured by the operation of a
law, by which the intermixture of different
gases is provided for. In order to understand
this, we must know something of the life of a
plant. In its process of respiration, as in
that of man, one kind of gas is emitted, and
another inhaled. The gas given out differs
in weight and other qualities from the
surrounding air; but, in obedience to a law
known among chemists as the "diffusion
law," it finds its way out between the glass
and the case; the external air, in like manner,
effects an entrance, and this interchange
continues until an intimate blending of the
two is effected. The carbonic acid gas
exhaled by man is incapable of sustaining life;
and, being heavier than the atmosphere, it
would, but for this law, accumulate in rooms
and on the surface of the earth, and produce
the most destructive results. In obedience to
this, however, as soon as given out, it begins
to ascend in opposition to the laws of gravity,
and soon becomes lost in surrounding space.
Such are some of the unseen processes going
on around us, and thus marvellous are the
silent workings of Nature! Another important
influence exercised by the glass consists
in keeping the plants in a perfectly tranquil
atmosphere, and thus enabling them to bear
much greater degrees of heat and cold than
they could do if exposed to currents or even
the ordinary agitation of the air, protecting
from the injurious effect of these the full-
blown flower, and preserving it fresh and
perfect much longer than when it is exposed.
Even cut flowers placed in a vase containing
water will last much longer if protected by a
bell-glass. In short, we isolate our plants,
place them as it were in a world of their own,
where all noxious influences are excluded, and
they are furnished with everything necessary
for their life and growth.

The various modifications in the form and
contents of the case are mere matters of taste.
Its applications are various. It affords every
inhabitant of the town the opportunity, at
comparatively trifling expense and trouble, of
enjoying, on a limited scale, the beauties of
nature. Instead of the wearying view of walls
and houses, he may, at one of his windows,
have an elegantly constructed case, filled with
fairy roses, fuchsias, heaths, &c., or with the
graceful forms of ferns, and dwarf palms,
delighting by their delicate tracery and varied
tints. Or, if means permit, a case of larger
magnitude may be built out from a study or
breakfast-room, and a model of some old ruin
be erected, or broken rock-work, with a
fountain-basin in the centre, and plants
dispersed around. Another advantage offered
by this plan is, that if the cases are kept in
the ordinary sitting-room which has a fire in
it daily during the colder period of the year,
the denizens of a warmer clime will grow
therein with perfect luxuriance, delighting us
with their verdure in the depth of winter,
and when the snow is on the ground, and the
bosom of mother-earth closed up by frost,
reminding us of a brighter and more genial
season. To all who preserve a healthful and
natural feeling, the "Ward Case" will afford
varied and continual pleasure, reminding them
of vegetation of larger growth, and of scenery
more expanded and majestic. Constant
gratification, too, is afforded by watching the
growth of plants, especially of the ferns, which
exhibit fresh beauties at every stage of their
development; whilst amid the hurry of business
and the anxieties of life, even a momentary
glance at these humble members of
creation thus fulfilling the purposes of their
existence, cannot fail of imparting
tranquillity to the troubled spirit.

To the sick room they are peculiarly
adapted, and their office here is indeed that
of "ministering angels." We know of no
present so cheering and acceptable to the
wasted sufferer as flowers. We have seen the
victim of disease, worn out by pain, and
almost dead to external impressions, suddenly
revive at their appearance, and the
countenance light up as these friends of
childhood were again welcomed. But the loveliest
flowers are, at times, objectionable from their
exhalations; when cut, too, they are but short-
lived, and in severe seasons it is extremely
difficult to procure a constant supply. None
of these objections can apply to the closed
case, for when the plants are once inserted,
they require little or no attention, the perfume,
if there be any, is confined, and many
preserve their freshness in the coldest seasons.