1 86 A RESPIRATION CALORIMETER. 



of the amount of water which flows through the absorbers and the 

 difference between the temperature of the water as it enters and as it 

 leaves the chamber. These determinations are given in column (a). 



Part of the heat generated within the respiration chamber is brought 

 away as latent heat of the water vapor carried out in the ventilating air 

 current. The amount of heat brought out in this way, being simply the 

 amount necessary to vaporize the water, is calculated from the amount 

 of water vaporized. The amount of water vapor for each experimental 

 period, shown in column (e), is taken from column () of Table 8, and 

 the amount of heat necessary to vaporize it is calculated from the quan- 

 tities in column (e) by use of the factor 0.592 as the latent heat of vapor- 

 ization of water per gram. These values are given in column (/). 



In addition to the above, a certain amount of heat is concerned in the 

 changes in temperature of the walls of the respiration chamber and 

 other parts of the apparatus. Each degree of change of temperature for 

 the whole calorimeter is assumed to represent 60 calories of heat. The 

 difference between the initial and final temperatures of each period gives 

 the total change of temperature to be taken into account. These data 

 are shown in column (). Multiplying these values by 60 gives the 

 total quantity of heat involved in the changes of temperature, as shown 

 in column (c). 



Food materials, dishes, etc., when sent into the chamber through 

 the food aperture, of course deliver heat when they are warmer than 

 the air of the chamber, and remove heat by absorption when they are 

 cooler. The amount of heat thus introduced or removed during the 

 different periods of the experiment, as calculated from the weight and 

 specific heat of each material and the difference between its temperature 

 and that of the chamber, is shown in column (rf). 



The total amount of heat determined in an experimental period, 

 column O) , is therefore the algebraic sum of the quantities of heat 

 brought away by the circulating water current, as shown in column (a), 

 with the correction due to changes in temperature of the calorimeter, 

 column (V), the correction for heat removed or introduced by food, 

 dishes, etc., column (rf), and the heat latent in the water vaporized, 

 column (/"). 



It should be added that the temperature of the ventilating air current 

 is so regulated as to be the same in entering as in leaving, so that it 

 carries out the same amount of heat as it brings in, and need not be 

 taken into account in the tables. 



No corrections have been made for variations in heat measurement 

 due to changes in body temperature, changes in body weight, or to the 

 absorption and radiation of heat by the bed and bedding, as previously 



