RESPIRATORY METABOLISM IN INFANCY AND IN CHILDHOOD: XVII. THE DAILY HEAT PRODUCTION OF INFANTS—PREDICTIONS BASED ON THE INSENSIBLE LOSS OF WEIGHT COMPARED WITH DIRECT MEASUREMENTS

Calorimetric studies of basal metabolism have demonstrated that the human subject from infancy to old age eliminates a constant proportion, approximately 25 per cent, of the heat produced by basal metabolism in the vaporization of water through the skin and lungs.1 Since water vapor forms under basal conditions a relatively fixed fraction of the total insensible perspiration (insensible loss of body weight) as measured with the balance, Benedict and Root2 used the latter as a simple and practical method for predicting the basal metabolism of adults, and Levine, Wilson and Kelly3 subsequently applied this method of prediction to infants in the basal state. The procedure was next extended by Newburgh and his colleagues4 to estimations of the total heat production of adults under maintenance conditions over long periods. These workers5 soon modified their original procedure by utilizing the water vapor alone (H2O) rather