1 62 HUMAN PHYSIOLOGY 



Income (food -f- oxygen) 3480 containing 321 C, 21 N, 30 salts 



Outgo 3342 " 280 " 21" 30 " 



Difference +138 +41 C 



This table teaches us the following facts : 



1. The person was in nitrogenous equilibrium, for the 

 nitrogen of the outgo equals the nitrogen taken in with 

 the proteids of the food. 



2. The person was not in carbon equilibrium, for the out- 

 go contains 41 g carbon less than the income. These 41 g 

 carbon have been stored up in the body. 



From the figures of the nitrogen it can be calculated that 

 69 g carbon originated from the ingested and decomposed 

 proteid. Of the 321 g carbon ingested and of the 280 g 

 carbon going out, 69 g originated from the proteid, hence 

 252 g carbon in the form of non-nitrogenous food has been 

 ingested. Of this, 21 1 g [280 69] was given off, hence 

 4.1 g of carbon in the form of a non-nitrogenous substance is 

 stored up in the body. 



3. Whether this 41 g carbon is stored up in the form of 

 fat or carbohydrate can be determined from the value of the 

 respiratory quotient. The volume of the exhaled carbon 

 dioxide amounts to 464 litres ; the volume of the consumed 

 oxygen is 503 litres. This would give us the value of the 

 respiratory quotient: 



vol. CO 9 464 



R.Q. = r ^- = - - = 0.92. 



vol. O 2 503 



This respiratory quotient is less than one, i.e. some of the 

 oxygen inhaled has been used to oxidize hydrogen. It is, 

 however, much larger than that of proteid, which is to say, 

 that, beside the proteid, but little fat and much carbohydrate 

 has been consumed. 



The following may still be said concerning the respiratory 

 quotient. By calculation it will be found that 53 g of the inhaled 

 oxygen have been used up, not in the oxidation of carbon, but in 

 the formation of water. The hydrogen necessary for this has been 

 derived from proteids and fats not from carbohydrates, for they 

 contain sufficient oxygen to unite with all the hydrogen. 



