NORMAL PROCESSES OF ENERGY METABOLISM 627 



temperature measurements made by rectal thermometer. It is conceivable 

 that the processes of involution, which were not yet entirely complete 

 at the time of the above observations were made, set free decomposition 

 products which stimulate tlie general heat production in a manner anal- 

 ogous to the stimulation of the mammary glands by fetal products. If 

 so, the processes by which heat is lost from the body (evaporation of water, 

 radiation and conduction) must be equally stimulated, for there is no 

 accumulation of heat. A state of hyperactivity of the sweat-glands, es- 

 pecially during the early days of the puerperium, is a phenomenon well 

 known to obstetricians and it is possible that this activity is a primary 

 cause of the increased heat production a cooling of the body surface 

 generally resulting in a reflex stimulation of the heat-producing tissues. 

 The writer believes, however, that the most important factors are the 

 activity of the mammary glands and the specific dynamic action of the 

 foodstuffs burning especially the increased protein combustion due to 

 involution of the uterus. The lower respiratory quotient found in the 

 puerperium is to be ascribed to the restricted diet very commonly imposed 

 immediately after delivery, and is a sign that the patient has used up her 

 store of glycogen during labor and is thrown back on her reserve of fat, and 

 on the protein resorbed from the uterus for her supply of energy. The 

 dynamic action of the latter would considerably increase the heat pro- 

 duction. 



F. Energy Metabolism of the Newborn 



Infant 



1. The Respiratory Quotient of the Newborn. In the observations 

 of Mensi, Scherer, and Babak, the respiratory quotient of the newborn 

 child was found to be extremely low, so much so that it was inferred that 

 oxygen must be utilized in the infant's body for some other purpose than 

 that of combustion. More recent observations have discredited this inter- 

 pretation, for it has been rendered very probable that the technique of 

 the early observers was seriously at fault. Hasselbalch points out that 

 Scherer's oxygen must have contained a much larger percentage of nitro- 

 gen than he assumed, from an old analysis, to be present ; also that there 

 was an admitted error of 6 per cent on the carbon dioxid. 



Hasselbalch (a) himself obtained quotients which were much higher. 

 Since his technique seems to have been carefully controlled, it is probable 

 that his results are much more reliable. In fact, Hasselbalch lays stress 

 on the fact that the R. Q. of the newborn infant before it begins to take 

 food is often much higher than that of an adult in a similar state of inani- 

 tion, and he thinks it is fair to infer that in such cases, which in his tables 

 include both the well-nourished infants born at term and infants prema- 



