QUANTITY OF RESPIRATION. 711 



and 104, without taking into account the hydro- 

 gen that unites with oxygen in the lungs. It would 

 also follow, that in the polar regions, where the 

 mean temperature is at 0, 104 per cent, more ca- 

 loric is obtained by respiration than in the middle 

 latitudes where the air is at 50 170 per cent, 

 more than within the tropics where the annual 

 average is 82, 375 per cent, more during winter 

 in the polar regions, where the temperature is 

 70 below 0, than where it is at 1 10, as in central 

 Africa, and 416, per cent, more than at 130, as 

 when exposed to a tropical sun. But if we take 

 the mean results of Crawford and Lavoisier, it 

 may be found by an easy calculation, that 38 per 

 cent, more oxygen is consumed at 50 than at 82, 

 97 per cent, more at 0, 215 per cent, more 

 at 70, below than at 1 10, and nearly 240 per 

 cent, more than at 130. 



Again, as I have shown it to be a law of nature, 

 that the aggregate forces of life in animals are in 

 proportion to the amount of caloric that passes 

 through their tissues in a given time, it might be 

 supposed, that they are more energetic in the 

 polar regions than in temperate, warm, and tropi- 

 cal climates. But notwithstanding the large 

 amount of caloric obtained by respiration, it is 

 still more rapidly abstracted by the surrounding 

 air, in excessively cold climates, and before it 

 has time to perform fully, its life-giving office 

 of nourishing the solids. Hence it is, that the 



3 A 



