52 



GASEOUS METABOLISM OF INFANTS. 



The barometer record in millimeters is also shown in table 17. From 

 the psychrometer observations the humidity of the air within the appa- 

 ratus is known. Deducting from the barometric pressure the tension 

 of aqueous vapor (11.1 mm.) for this observed humidity, allowance is 

 made for the volume of water- vapor present within the apparatus. The 

 corrected barometer reading, p, is then used. 



The total volume of the apparatus is 81.5 liters. In order to deter- 

 mine the total volume of water-free air under standard conditions of 

 temperature and pressure, i. e., 0° C. and 760 mm., to the logarithm of 

 this total volume is added, first, a logarithmic factor for the average 

 temperature recorded and, second, a logarithmic factor for the corrected 

 pressure. These factors are obtained from tables which have been 

 prepared for the purpose. The standard temperature reduction is rep- 

 resented by the formula -., , , U representing the temperature of the 

 apparatus. The reduction factor of pressure for standard conditions 

 is obtained from the ratio J™, in which p represents the corrected 



barometer. The total volume of oxygen and nitrogen is then obtained 

 from the total volume of water-free air by deducting the volume of 

 carbon dioxide as determined by the analysis with the Pettersson- 

 Palmquist apparatus. No attempt is made to separate the volume of 

 nitrogen, since the amount of this gas remains unchanged and the 

 absolute amount of oxygen is not desired. 



Measurement of the carbon dioxide absorbed and the oxygen admitted. — 

 The records of the carbon-dioxide production and oxygen consumption 

 for the first period of the experiment are given in table 18. The carbon 



Table 18. — Carbon dioxide absorbed, oxygen admitted, and alcohol burned in the first 

 period of alcohol check experiment. 



Oxygen admitted. 1 



Weights of oxygen cylinder: 



Start 3408.41 gm. 



End 3405 . 00 gm. 



2 = 3.41 gm. 



Impurity correction — .01 gm. 



Spirometer correction — . 03 gm. 



Total 2 = 3 . 37 gm. 



Carbon dioxide absorbed. 

 Weights of absorbers, G+44: 



End 5125.90 gm. 



Start 5122.78 gm. 



C0 2 = 



3.12 gm. 



Alcohol burned. 



One gram 92.56 p. ct. absolute alcohol yields 

 1.769 gm. CO2 and requires 1.930 gm. 2 . 



Burette readings: 



ll h 30'" a. m 0.590 c.c. 



12 11 p.m.... 2.770 c.c. 



Difference 2 . 180 c.c. at 21 . 05° C. = 



2.169 c.c. at 15.6° C. 



2.109 c.c. (sp. g. 0.81576) = 1.769 grams 



(C 2 H 6 OH). 

 1 . 769 X 1 . 769 = 3.13 gm. C0 2 produced. 

 1.769 X 1.930 = 3.41 gm. 2 used. 



J The calculations are here made on weight. For a method of determining the oxygen con- 

 sumption by volume, see Benedict, Deutsch. Archiv f. klin. Med., 1912, 107, p. 181. 



