Metabolism Experiment No. 68. 



63 



previously. They depend in large measure upon the barometric conditions and 

 the temperature, as well as the quantity of nitrogen admitted with the oxygen. 

 Sufficient experimental evidence has accumulated, however, to show that at least 

 under the conditions obtained in these experiments no noticeable effect on the 

 respiratory exchange can be attributed to relatively marked changes in per- 

 centages of either carbon dioxide or oxygen in the residual air. 



The quantity of carbon dioxide exhaled on the first day, i. e., 694.3 grams, 

 is somewhat larger than that on the second day, 679.3 grams. The quantities 

 of oxygen consumed were practically identical for the two days. 



1 Includes also water of perspiration. 



Matebial Katabolized in the Body. 



The losses of elements in the body are obtained from chemical analyses of 

 the urine and air. In table 26 are recorded the factors of income and outgo 

 expressed in terms of chemical elements, the ash here being treated as an 

 element. The data are drawn from the preceding tables, and are used as 

 explained on page 37. The balance shows that on the first day there was a loss 

 in total weight of 1801.40 grams, which consisted of 12.26 grams of nitrogen, 

 199.12 grams of carbon, 192.65 grams of hydrogen, 1386.46 grams of oxygen, 

 and 10.91 grams of ash. Similarly on the second clay, the outgo is greater 

 than the income by 1641.22 grams, consisting of 13.03 grams of nitrogen, 

 195.61 grams of carbon, 176.55 grams of hydrogen, 1244.43 grams of oxygen, 



