HOW CHILDREN GROW.
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.