The water which they decompose affords them nourishment for the
support of their vital juices, and enables them, by combining the
fluid gases which compose it with those of the air and the soil, to
form their different products; while the superfluous gas is abundantly
given out by their leaves, to refresh the spent air, and render it
wholesome for the animals that breathe it.

_Vital_, belonging to life, necessary to existence.

_Superfluous_, unnecessary, not wanted.


What is Rain?

The condensed aqueous vapors raised in the atmosphere by the sun and
wind, converted into clouds, which fall in rain, snow, hail, or mist:
their falling is occasioned by their own weight in a collision
produced by contrary currents of wind, from the clouds passing into a
colder part of the air, or by electricity. If the vapors are more
copious, and rise a little higher, they form a mist or fog, which is
visible to the eye; higher still they produce rain. Hence we may
account for the changes of the weather: why a cold summer is always a
wet one--a warm, a dry one.

_Aqueous_, watery; consisting of water.

_Collision_, a striking together, a clash, a meeting.

_Electricity_, a natural agent existing in all bodies (see
page 18).