the weight of children, decrease of warmth by decreased weight. He found a decrease of 2° in temperature to be accompanied by as much as a ninefold decrease in the weight of a child, while a rise of 3° was followed by a thirteenfold increase in weight.
Weight decreases in proportion as the temperature falls, for the same reason that growth is hindered by cold.
Since growth is so strongly influenced by cold, a knowledge of the normal growth-rate is invaluable to those who have the care of children, as deviations from that normal rate are a sure index to impaired nutrition and general health. In order to ascertain whether such deviations are going on, children should frequently be weighed and measured, for in the one word growth I include increase both in weight and in height.
All infants lose five or six ounces in weight during the first few days after birth; they, however, gain one pound by the end of the first month, and two pounds in the second, after which the increase is less rapid. In the first four or five months the weight at birth should be doubled, and trebled by the end of the first year. During this time the child should gain three inches in height in the first three months, two inches in the next quarter, and two or three inches in the last six months. At three years old the average child is three feet high, and weighs thirty-two pounds; at five years it weighs forty pounds; at eight years its height is four feet, weight fifty-six pounds; at twelve it is
