600 PHYSIOLOGY: BENEDICT AND TALBOT 
much higher than in walking, this is surprising. On the other hand, 
in the walking experiments there was, as is customary with trained 
walkers, considerable arm motion which was absent in the running 
experiments. Basal experiments made while the subject was standing 
still but swinging the arms in essentially the same ampHtude and rhythm 
as when walking showed a great increase in the resting metabolism. 
The use of this base line reduces the progression constant for walking 
to 0.780 gram-calorie with an average speed of 144 meters per minute. 
This debatable procedure seems to emphasize the fact that for the 
most economical transport of the body, with or without superimposed 
load, some type of gait which reduces to a minimum the elevation of the 
body and the extraneous arm motion is most desirable. 
The details of this research are reported in Publication No. 231 of the 
Carnegie Institution of Washington. 
THE PHYSIOLOGY OF THE NEW-BORN INFANT 
By Francis G. Benedict and Fritz B. Talbot 
NUTRITION LABORATORY. CARNEGIE INSTITUTION OF WASHINGTON 
Preseqted to the Academy, November 2, 1915 
The physiology of the first week of life is of especial importance owing 
to the unique position of civilized woman who, alone of all mammals, 
is usually for several days so completely exhausted by labor as to make 
her existence and even that of her child absolutely dependent upon the 
ministrations of others. The insufficiency of the breast secretion, the 
loss in weight of the infant, which almost invariably occurs, and the too 
frequent but rarely needed complete substitution of bottle feeding for 
breast feeding make a study of the actual needs of the new-born infant 
of unusual interest. 
In a research carried out by the Nutrition Laboratory, in which a 
respiration chamber was used, measurements were made of the carbon- 
dioxide output and the oxygen intake, and records were secured of the 
pulse-rate, respiration-rate, and body-temperature of 105 new-born 
infants. The observations often began before the infant was 1 hour 
old, the child being placed in the respiration chamber as soon as it had 
been bathed and dressed. The metabolism was then studied, frequently 
in 1-hour periods, for several consecutive hours. The primary object 
of the research was to determine the basal minimum metabolism of the 
infant with special reference to sex, weight, age, and length. 
From the data obtained in these observations, the respiratory quo- 
tients were computed which indicated the nature of the principal sub- 
