than half attain the age of military service, which in Russia is twenty-five, and of these at least one million, that is, more than one-fourth, are found to be unfit for the army, owing to their shortness of stature and physical debility.
This last fact illustrates another point of great importance—namely, that those who survive exposure to cold are injured by it, either in growth or in development.
The subject of growth is inextricably interwoven with those of nutrition and heat. Spencer, in his great work on "Biology," states1[1] that growth is substantially equivalent to the absorbed nutriment, minus the nutriment used up in action. This is a short way of saying that growth is supplied by digested food, but only by the surplus of digested food which is left after replacing the worn-out tissues that are constantly being used up in the body, and the heat which is constantly passing away from it. Thus the more heat that is lost from the body, the more nutriment has to be confiscated for heat-giving purposes, and the less can be devoted to building up the body. Hence cold is an enemy to growth alike in the animal and vegetable world.
An interesting series of experiments bearing on this subject has been instituted by Mailing-Hansen, and the results of these experiments were made public by him at the International Medical Congress of 1884, held at Copenhagen. He finds that increase of warmth is accompanied by increase in
- ↑ 1 Vol. i. p. 122.
