1 82 A RESPIRATION CALORIMETER. 



The quantity of water removed from the air current during each period 

 is determined by weighing the water- absorbers at the beginning and end 

 of the period. The values thus found are expressed in column (/"). 

 The quantity of water in the air remaining in the chamber at the end 

 of each period is learned by analysis of a sample of the air. These 

 determinations are given in column (a). The increase or decrease in 

 the quantity of vapor residual in the air for each period, which is simply 

 the difference between the quantity at the end of one period and that 

 at the end of the next, is given in column () , an increase being indi- 

 cated by + and a decrease by . 



The quantity of water exhaled by the subject during each period, 

 shown in column (g}, is the algebraic sum of the quantities in columns 

 () and (/). If the value is indicated by + in column () it is added, 

 because it represents an excess that has been added by the subject 

 during the period ; it is subtracted when the sign is , because that 

 means that the absorbing apparatus has removed from the air so much 

 more than was exhaled by the subject. 



As a result of the variation in hygrometric conditions inside the respi- 

 ration chamber, there may be a noticeable change in the amount of 

 moisture deposited upon the bedding, clothing, etc., of the man and 

 also upon the heat-absorbing system. In general, this latter is negli- 

 gible in the case of the rest experiments, such as experiment No. 70 

 reported here. On the particular day here given there was a loss 

 of weight in the heat-absorbing system amounting to 2 grams, and an 

 increase in weight of the chair, bedding, etc. , of 5. 26 grams. These are 

 recorded in columns (c) and (aT), Table 8. In column (e) the algebraic 

 sum of (), (c) t and (d} is given. Obviously, for the entire day the 

 total water of respiration and perspiration is the algebraic sum of (tf) 

 and (/) and not of (6) and (/). 



STATISTICS OF CARBON DIOXIDE ELIMINATED. 



The determinations of the quantity of carbon dioxide exhaled by the 

 subject during each period depend, like those for water, upon the quan- 

 tity removed from the ventilating air by the absorbers and that remain- 

 ing in the air within the apparatus. These data for carbon dioxide are 

 summarized in Table 9. The determinations of the total quantity of 

 carbon dioxide removed from the air current during an experimental 

 period, ascertained by weighing the absorbing apparatus at the beginning 

 and end of each period, are shown in column (V). The quantities of 

 carbon dioxide remaining in the air of the chamber at the end of each 

 period, as determined by analysis of a sample of the air, are shown in 

 column (a). The difference between the quantity residual in the air 

 at the end of one period and that at the end of the next period is shown 



