YOUNG WOMEN DOING LIGHT HOUSEHOLD WORK. 91 



tainer, the carbon dioxide absorbed from the air passing through 

 the lo-millimeter openings may be quantitatively determined. 



The exact proportion of air passing through the lO-milHmeter 

 openings was found by admitting a known weight of carbon dioxide 

 to the chamber from a steel bottle of the liquefied gas, and determin- 

 ing the amount of this gas which passed through each opening. In 

 the present apparatus this happens to be exactly lo per cent, of the 

 total, L e., 10 per cent, of the air is delivered through each of the 

 lo-millimeter openings and 80 per cent, through the 29-millimeter 

 aperture. The weight of carbon dioxide absorbed in the purifying 

 vessel, corrected for the amount of carbon dioxide contained in the 

 incoming air (a correction obtained by a simple calculation), is 

 therefore exactly one tenth of the total amount produced in the 

 chamber during the experiment, provided no change has taken place 

 in the percentage of carbon dioxide residual in the chamber air. 

 Analyses of the residual air, made with a Haldane apparatus at the 

 beginning and end of the period, give this correction, and the true 

 carbon-dioxide production is thus rapidly determined. 



With this respiration chamber, experiments with periods no 

 longer than twenty minutes are perfectly practicable. The de- 

 termination of the carbon-dioxide production has of itself but little 

 value, but is used for computing the heat production by means of the 

 calorific value of carbon dioxide at an assumed respiratory quotient. 

 Such a method is admittedly not so accurate as the direct measure- 

 ment of the heat production, or the computation of the heat produc- 

 tion from measurements of the oxygen consumption. It is, how- 

 ever, a rapid method and not too costly for determining the approxi- 

 mate heat output of a group of people. 



Through the personal interest of Professor Alice F. Blood, 

 several groups of Simmons College undergraduates were interested 

 in the research and volunteered to act as subjects for this series of 

 experiments. The studies were made with over two hundred 

 women. In this research the standard values used for comparison 

 were not obtained under the usual experimental conditions for de- 

 termining basal metabolism, that is, twelve hours after the last meal 

 and with the subject lying down in complete muscular repose, but to 



