694 
DE. E. SMITH OH THE CHEmCAL 
since the degree of exertion and other circumstances are not recorded by the latter, 
and hence it is impossible to appreciate the state of the system to which they refer. 
It is noticeable how great is the difference amongst men in the amount of carbon 
which they expire — a fact which has been obseiwed by all inquii'ers. Thus Professor 
Feankland and myself differed as 2 to 3, and yet we were nearly of the same age and 
height, but differed greatly in weight and robustness of constitution. Each person also 
differs much at various periods— a circumstance noticed by Baeeal. ]SL-. Moul varied 
as 10 to 11, and I at least as 11 to 12. Hence it is safer to adopt comparative rather than 
absolute quantities in determining the quantity of carbonic acid exhaled per day by any 
individual. Thus if the amount of carbonic acid exhaled in a state of quietude in the 
day-time be determined by observations made at various periods of the day in relation 
to the meal hours, the amount exhaled during six hours of the night may be determined 
by allowing the amount of 3^ hours of the day ; and in reference to exercise, by allow- 
ing If hour rest for one hour of walking at two miles per houi-, and 2f hours of rest 
for one hour of walking at three miles per hour. 
B. Quantity of Air ins;pired. 
In the four series of inquiries now recorded, the quantity of air insphed in cubic inches 
during the working day was per minute as follows 
Continuotis inquiries. 
March. 
May. 
r 
March. 
N 
August. 
cub. in. 
cub. in. 
cub. in. 
cub. in. 
Myself 
675 
531-5 
582-1 
583 
Mr. Moul . . . 
483T 
431-7 
Dr. Murie 
Professor Fraiikland 
464-5 
364-4 
The average quantity inspired by myself was 567 ’7 cubic niches, and by ISIi'. Motl 
457’4 cubic inches, whilst the average of all the observations was 502 cubic inches per 
minute. 
Ill order to determine the proportion which the quantity of air inspired bears to the 
carbonic acid collected (for as I have not measured the expired air I cannot take that 
as a point of comparison), I insert the following statement of the amount of carbonic acid 
per minute which was actually collected, with the quantities of air which have just 
been given. It is as follows : — 
Continuous inquiries. 
March. 
May. 
March. 
August. 
Average. 
Carb. acid. Air. 
Carb. acid. Air. 
Carb. acid. Air. 
Carb. acid. Air. 
Carb. acid 
grs. cub. in. 
grs. cub. in. 
grs. cub. m. 
grs. cub. in. 
grs. 
Myself. . 
8-75 576 
10 531-5 
9-5 582-1 
10-9 583 
9-79 
Mr. Moul 
8-6 483-1 
8-06 431-7 
Dr. Murie 
7-93 464-5 
Professor Frankland 
6-66 364-4 
