Metabolism of Healthy Children during Sleep. 63 
36 (568) 
The metabolism, directly determined, of healthy- 
children during sleep. 
By JOHN HOWL AND. 
[From the Department of Physiology, Cornell Medical College, 
New York.] 
Through the kindness of Dr. Lusk these experiments were 
made in conjunction with him, Dr. Williams and Mr. Riche. 
As yet experiments have been made on only two children, but 
the results are given on account of the interest attaching to the 
first direct determination of heat produced by children. 
The children were healthy, were gaining weight and were fed 
every four hours so as to keep their metabolism as constant as 
possible. They were put on the portable metabolism apparatus 
devised by Dr. Du Bois that allows great freedom, accurate col- 
lection of all the urine and feces and no discomfort. They were 
kept awake during the forenoon, fed at 1 p.m. and put at once into 
the calorimeter where they usually slept throughout the whole 
experiment. 
Some of the results are given in the chart. It will be seen that 
the amount of heat produced varied considerably from hour to 
hour, and that during the same hours of different days with a con- 
stant diet the heat produced is not the same. The average for 
the hours in which the conditions were entirely satisfactory was 
14.18 calories. The metabolism directly determined compared 
moderately with the metabolism as calculated in about half the 
cases. In the other half of the cases a low respiratory quotient 
indicated an erroneous oxygen determination, which invalidated 
the calculations. 
Comparing the results in the two children it is found that the 
second, McG., regularly gave off more heat than the first (Newman) 
and that his heat production per square meter of surface per 24 
hours was much greater. This is undoubtedly due to the greater 
surface area of the second child which fails to show by the ordina ry 
formula for calculating the surface area (12.3 x ^weight 2 ). 
Tne second child, McG. was 8 months old, weighing 4.320 kilos, 
