598 METABOLISM 



TABLE I 



THE PERCENTAGE OF OXYGEN WHICH is EQUIVALENT TO THE NITROGEN FOUND IN THE 



EXPIRED AIR 



To obtain the nitrogen in the expired air, add the percentage of CO 2 and O 2 found 

 and subtract the sum from 100. The table gives the percentage for O 2 corresponding to 

 this figure : 



%N a 78.7 78J3 78^9 79^0 79O 79^2 79^3 79^4 79J5 79^6 79/7 79.8 



%0 2 20.86 20.88 20.90 20.93 20.96 20.98 21.01 21.04 21.07 21.10 21.12 21.14 



79.9 80.0 80.1 80.2 80.3 80.4 80.5 80.6 



21.16 21.19 21.22 21.25 21.28 21.31 21.35 21.38 



TABLE II 

 TENSION OF AQUEOUS VAPOR IN MILLIMETERS OF MERCURY 



To obtain the dry barometer pressure, subtract the mm. Hg corresponding to the 

 temperature of the air from the barometer pressure at the time of the experiment: 



Temp. 15 16* 17 18" 19 20 21 22 23 24 25" 

 Mm. 12.7 13.5 14.4 15.4 16.3 17.4 18.5 19.7 20.9 22.2 23.5 



TABLE III 



TEMPERATURE CORRECTIONS TO REDUCE READINGS OF A MERCURIAL BAROMETER WITH A 



BRASS SCALE TO 0C. 



Subtract the appropriate quantity as found in table from the height of the barometer. 

 The table is for a barometer with a brass scale, and the values are a little lower (about 

 .2 mm.) than for the glass scale. The corrections for intermediate temperatures can be 

 approximated by interpolation. 



TABLE IV 

 TABLE FOR REDUCING GASEOUS VOLUMES TO NORMAL TEMPERATURE AND PRESSURE 



The observed volume, when multiplied by the factor corresponding to the temperature 

 and corrected pressure, will give the volume of the expired air reduced to and 760 mm. 



