TO THE ANIMAL HEAT. 25 



heat. In fact, observation proves that the hydrogen 

 of the food plays a not less important part than 

 the carbon. 



The whole process of respiration appears most 

 clearly developed, when we consider the state of 

 a man, or other animal, totally deprived of food. 



The first effect of starvation is the disapj^earance 

 of fat, and this fat cannot be traced either in the 

 urine or in the scanty faeces. Its carbon and hydro- 

 gen have been given off through the skin and lungs 

 in the form of oxidised products ; it is obvious that 

 they have served to support respiration. 



In the case of a starving man, 32^ oz. of oxygen 

 enter the system daily, and are given out again in 

 combination with a part of his body. Currie men- 

 tions the case of an individual who was unable to 

 swallow, and whose body lost 100 lbs. in weight 

 during a month ; and, according to Martell (Trans. 

 Linn. Soc, vol. xi. p. 411), a fat pig, overwhelmed 

 in a slip of earth, lived 160 days without food, and 

 was found to have diminished in weight, in that 

 time, more than 120 lbs. The whole history of 

 hybernating animals, and the w^ell-established facts 

 of the periodical accumulation, in various animals, 

 of fat, which, at other periods, entirely disappears, 

 prove that the oxygen, in the respiratory process, 

 consumes, without exception, all such substances as 

 are capable of entering into combination with it. 

 It combines with whatever is presented to it ; and 

 the deficiency of hydrogen is the only reason why 



