MEMOIRS OF THE NATIONAL ACADEMY OK SCIENCES. 



299 



The quantity of water exhaled by the subject in the different periods of the experiment arc 

 shown in Table XII. Unlike the carbon dioxid. the major portion of the water exhaled is con- 

 densed either within the chamber as drip, upon the surface of the absorbers, or in the "freezer" 

 cans, which are immersed in a brine tank cooled to about — 20 O, and through which the venti- 

 lating air current passes. Table XII shows the amount of water in the ingoing air, the amount 

 in the outgoing air not condensed in the freezers, and the correction for water remaining in the 

 chamber. The final column of the table shows the total water of respiration and perspiration 

 during the different periods of this experiment. 



Table XII. — Record of watt r in vt ntilating air cum ut — Metabolism < rpt rim, nt Xo. l .'. 



Meat measurements. — The details of the measurements of heat given off by the subject during 

 the experiment are too extensive to be given here. Those for each hour of the day and night, as 

 recorded, till a page of a notebook sheet 22 by 29 cm. For a detailed description of the appliances 

 for determining the amount of heat carried out by the water current and for avoiding gain or loss 

 of heat from the apparatus except where it can be determined, reference may be made to an 

 earlier publication on this subject. " As has already been explained (see p. 237), the larger 

 part of the heat given off by the subject is carried away in the water current, whose temperature 

 as it enters and leaves the apparatus is determined at intervals of from 2 to 4 minutes, and 

 whose quantity is measured in cylinders holding 10 liters each. The average difference in 

 temperature between the incoming and outgoing water multiplied by the number of kilograms 

 of water which has passed through the chamber gives the number of calories of heat removed 

 during the time. Since, however, the specific heat of water varies at different temperatures, it 



a Bulletin 63 of Office of Experiment Stations, above referred to. 



