of Respiration at different Periods of the Day. 409 



Total of 24 exp. 2728*37 - 2619*05 



2619-05 



.•. 109-32 parts were absorbed by the lime-water. 

 2728-37 : 109-32 : : iOO : 4-01 per cent. 



The average therefore of 24 experiments upon the air re- 

 spired between 9 p.m. and midnight, and comprising eight 

 days, indicates 4-01 per cent, of carbonic acid gas, which 

 corrected for tension will be 4*12 per cent. 



The average of all the experiments together, 124 in num- 

 ber, and comprising almost every hour of the day between 

 8 a.m. and midnight, and including a period of 8 days, 

 gives 



13895-53 : 553-32 :: 100 : 3-9819 per cent., which when 

 corrected for tension, indicates 4-09 per cent, as the total 

 daily average of the carbonic acid gas in the air respired 

 from the lungs. 



Epitome of the Results. 

 1st period 8 a.m. to 9^ a.m. 32 exp. indicated 4*37") ^^ » 



J =^s 



1 24 exp. comprising 8 days. 

 Hence we find the carbonic acid gas produced by respiration 

 to be a variable quantity, that it is less during the period of 

 active digestion, that it increases with increased abstinence from 

 food ; and that it varies in the same individual at similar 

 periods of dijj'crent days. It also appeared during these ex- 

 periments, that excitement oj any kind (whether from the ex- 

 hilar£\ting stimulus of wine, or from the irritating annoyances 

 which are wont to occur to most folks who are actively en- 

 gaged,) caused a diminution of carbonic acid in the air re- 

 spired, as compared with the ordinary average of that re- 

 spired at a similar period of the day, and during a state of 

 ordinary tranquillity. 2Vie total daily average indicated 4'09 



