soft, insensate body of the infant. The effect of air
on the new-born child is as remarkable in its results as it is wonderful
in its consequence; but to understand this more intelligibly, it must
first be remembered that life consists of the performance of _three_
vital functions--RESPIRATION, CIRCULATION, and DIGESTION. The lungs
digest the air, taking from it its most nutritious element, the
_oxygen_, to give to the impoverished blood that circulates
through them. The stomach digests the food, and separates the
nutriment--_chyle_--from the aliment, which it gives to the blood for
the development of the frame; and the blood, which is understood by the
term circulation, digests in its passage through the lungs the
nutriment--_chyle_--to give it quantity and quality, and the _oxygen_
from the air to give it vitality. Hence it will be seen, that, speaking
generally, the three vital functions resolve themselves into
one,--DIGESTION; and that the lungs are the primary and the most
important of the vital organs; and respiration, the first in fact, as we
all know it is the last in deed, of all the functions performed by the
living body.

THE LUNGS.--RESPIRATION.

2453. The first effect of air on the infant is a slight tremor about the
lips and angles of the mouth, increasing to twitchings, and finally to a
convulsive contraction of the lips and cheeks, the consequence of sudden
cold to the nerves of the face. This spasmodic action produces a gasp,
causing the air to rush through the mouth and nostrils, and enter the
windpipe and upper portion of the flat and contracted lungs, which, like
a sponge partly immersed in water, immediately expand. This is succeeded
by a few faint sobs or pants, by which larger volumes of air are drawn
into the chest, till, after a few seconds, and when a greater bulk of
the lungs has become inflated, the breast-bone and ribs rise, the chest
expands, and, with a sudden start, the infant gives utterance to a
succession of loud, sharp cries, which have the effect of filling every
cell of the entire organ with air and life. To the anxious mother, the
first voice of her child is, doubtless, the sweetest music she ever
heard; and the more loudly it peals, the greater should be her joy, as
it is an indication of health and strength, and not only shows the
perfect expansion of the lungs, but that the process of life has set in
with vigour. Having welcomed in its own existence, like the morning
bird, w