14 OXYGEN COMBINES WITH 



an adult, taking moderate exercise, consumes 13.9 oz. 

 of carbon daily, (s) 



These 13 T 9 oz. of carbon escape through the skin 

 and lungs, as carbonic acid gas. 



For conversion into carbonic acid gas, 13 T 9 oz. of 

 carbon require 37 oz. of oxygen. 



According to the analyses of Boussingault (Ann. de Ch. 

 et de Ph. LXXI. p. 136), a horse consumes in twenty- 

 four hours 97| oz. of carbon, a milch cow 69 T 9 S oz. 

 The quantities of carbon here mentioned are those given 

 off from the bodies of these animals in the form of 

 carbonic acid ; and it appears from them that the horse 

 consumes, in converting carbon into carbonic acid, 

 13lbs. 3| oz. in twenty-four hours, and the milch cow 

 11 Ibs. 10| oz. of oxygen in the same time. (4) 



Since no part of the oxygen taken into the system is 

 again given off in any other form but that of a com- 

 pound of carbon or hydrogen ; since, further, the car- 

 bon and hydrogen given off are, in a normal condition 

 of health, replaced by carbon and hydrogen supplied in 

 the food, it is clear, that the amount of nourishment re- 

 quired for its support by the animal body must be in a 

 direct ratio to the quantity of oxygen taken into the 

 system. 



Two animals, which in equal times take up by means 

 of the lungs and skin unequal quantities of oxygen, 

 consume quantities of the same nourishment, which are 

 unequal in the same ratio. 



The consumption of oxygen in equal times may be 

 expressed by the number of respirations ; it is clear 



