the chest, and
of the bowels.

Before entering on these new subjects, however, a few words may not be
out of place with reference to what may be termed the second period of
childhood. It is above all a time of wonderfully lessened sickness and
mortality. We have not the means of stating exactly the rate at which
mortality is lessened between the cessation of the first and the
commencement of the second dentition; but we do know that it is ten
times less between the age of one and five, and nearly twenty times less
between five and ten than it was in the first year of existence.[10] A
mother's anxiety then may safely be quieted after the first year of her
infant's life, and still more after the first set of teeth have been
cut, for if her child is strong and healthy then, there will be
comparatively little to fear for its future.

Four years or thereabouts now follow, before any important change takes
place in the child's condition, for it is not until between six and
seven years old that the first set of teeth begin to be shed, and the
second to take their place. This change of teeth too is of far less
moment as far as the health is concerned, than was the cutting of the
first set. The first dentition was the preparation for an entirely new
mode of life for the child, and was intended to fit it for a life
independent of its mother. The second has no such signification; it is a
mere local alteration rendered necessary by the growth of the jaws, and
takes place quietly, by the gradual absorption of the roots of the first
set of teeth, brought about by the pressure of the others as they
approach the surface. Four teeth in each jaw are new, and replace no
others, but usually they are cut without much discomfort, and the wisdom
teeth do not concern us here, for they do not appear until childhood has
long passed.

But, though between the age of two years and of ten there is no
important change, nor even preparation for a change in the constitution,
the time is yet one of most active growth of the body, and consolidation
of the skeleton. The stature increases from 2 ft. 6 in. to 4 ft. 6 in.,
and the weight nearly doubles, while at the same time the ends of the
long bones previously connected with the shafts by means of cartilage or
gristle, become firmly united by the conversion of that cartilage into
bone, and a similar process goes on, though not completed till later, in
the ribs and the breast bone.

Rapid increase of