During the International Medical Conference held in Copenhagen in the
summer of 1884, a paper read by the Rev. Mailing Hansen, Principal
of the Danish Institution for the Deaf and Dumb, was listened to
with marked attention and interest. It gave the results of the daily
weighing and measurements of height which he had carried on for nearly
three years on the one hundred and thirty pupils—seventy-two boys and
fifty-eight girls—of the Institution, and demonstrated facts as to
the development of the human body during the period of childhood that
perfectly startled and astonished the assembled medical authorities,
opening an entirely new field for investigation and reflection. Since
then, Mr Hansen has continued his observations; and though he has yet a
tremendous amount of work before him, he believes himself able to state
now the outlines of the results he has obtained.
The children are weighed four times daily in batches of twenty—in the
morning, before dinner, after dinner, and at bedtime, and each child is
measured once a day. The common impression is, no doubt, that increase
in bulk and height of the human body during the years of growth
progresses evenly all through the year. This is not so. Three distinct
periods are marked out, and within them some thirty lesser waverings
have been observed. As for bulk, the maximum period extends from August
until December; the period of equipoise lasts from December until about
the middle of April; and then follows the minimum period until August.
The lasting increase of bulk or weight is all accumulated during the
first stage; the period of equipoise adds to the body about a fourth of
that increase, but this gain is almost entirely spent or lost again in
the last period.
The increase in height of the children shows the same division into
periods, only in a different order. The maximum period of growth in
height corresponds to the minimum period of increase in bulk, and _vice
versâ_. In September and October a child grows only a fifth of what it
did in June and July. In other words, during a part of the year—autumn
and beginning of winter—the child accumulates bulk, but the height is
stationary. In the early summer the bulk remains nearly unchanged, but
the vital force and the nourishment are expended to the benefit of
height. While the body works for bulk there is rest for the growth,
and when the period of growth comes, the working for bulk is suspended.
The human body has, consequently, the same distinctly marked periods of
development as plants.