3 86 



PHYSIOLOGICAL CHEMISTRY. 

 OUTGO OBSERVED. 



The weight of the various excreted products is greatly in 

 excess of the visible income, but the oxygen inhaled has not 

 yet been calculated. The formula given above may be applied 

 to find this : 



Oxygen = A' + Excreta (A -f F) 



75,050 3,393 75,ooo 2,735 



78,443 77,735 



= 708 grams 

 = 495.4 liters. 



In the table above the volume of carbon dioxide eliminated is 

 given as 471 liters. The respiratory quotient is therefore 



--.* 



This gives us the first clue as to the nature of the foods metab- 

 olized. The factor is so much larger than that correspond- 

 ing to the fats that we may practically exclude these at once. 

 In any event there is a large protein metabolism since the orig- 

 inal nitrogen of the food is all found in the urine and the feces. 

 In other words we have nitrogen equilibrium, with no storing 

 up of protein in the tissues. The respiratory quotient corre- 

 sponds to the combustion of carbohydrates and proteins mixed. 

 If we assume for the moment that no fat is oxidized, this 

 calculation may be made. The 254.2 gm. of carbon in the car- 

 bon dioxide of respiration calls for 678 gm. of oxygen. The 

 difference between this and the calculated absorbed oxygen, 

 708 gm., amounts to 30 gm., which must be used up in oxi- 

 dizing hydrogen of protein substances. This conclusion is 



