nes of the infant
have been sufficiently expanded and solidified, is deposited in the
teeth, which consist at first only of a gelatinous membrane or case,
fitted for the reception of this salt; and which, after acquiring
hardness within the gum, gradually protrude from it.

CAROLINE.

How very curious this is; and how ingeniously nature has first provided
for the solidification of such bones as are immediately wanted, and
afterwards for the formation of the teeth, which would not only be
useless, but detrimental in infancy!

MRS. B.

In quadrupeds the phosphat of lime is deposited likewise in their horns,
and in the hair or wool with which they are generally clothed.

In birds it serves also to harden the beaks and the quills of their
feathers.

When animals are arrived at a state of maturity, and their bones have
acquired a sufficient degree of solidity, the phosphat of lime which is
taken with the food is seldom assimilated, excepting when the female
nourishes her young; it is then all secreted into the milk, as a
provision for the tender bones of the nursling.

EMILY.

So that whatever becomes superfluous to one being, is immediately wanted
by another; and the child acquires strength precisely by the species of
nourishment which is no longer necessary to the mother. Nature is,
indeed, an admirable economist!

CAROLINE.

Pray, Mrs. B., does not the disease in the bones of children, called the
rickets, proceed from a deficiency of phosphat of lime?

MRS. B.

I have heard that this disease may arise from two causes; it is
sometimes occasioned by the growth of the muscles being too rapid in
proportion to that of the bones. In this case the weight of the flesh is
greater than the bones can support, and presses upon them so as to
produce a swelling of the joints, which is the great indication of the
rickets. The other cause of this disorder is supposed to be an imperfect
digestion and assimilation of the food, attended with an excess of acid,
which counteracts the formation of phosphat of lime. In both instances,
therefore, care should be taken to alter the child's diet, not merely by
increasing the quantity of aliment containing phosphat of lime, but also
by avoiding all food that is apt to turn acid on the stomach, and to
produce indigestion. But the best preservative against complaints of
this kind is, no doubt, good nursing: when a child has plenty of air and
exercise, the digestion and assimilation wi