340 THE CHEMISTRY OF CREATION. 



as quickly as possible, in order that its newly 

 acquired properties may not be lost, by means 

 of several large blood-vessels, singularly straight 

 and simple, with a view to facilitate this ob- 

 ject, and re-enters the heart, which, by its in- 

 cessant toilings, despatches it on its life-giving 

 errand throughout the frame. 



The most recent results on the chemistry of 

 respiration discloses the following facts : * 



1. Warm-blooded animals exhale nitrogen in 

 proportion of from y^ to -^ of the oxygen con- 

 sumed in breathing. 2. Animals fed on fari- 

 naceous food exhale a measure of carbonic acid 

 exactly equal to the oxygen inspired ; but if fed 

 on animal food, they absorb oxygen sometimes 

 equal to ibur parts in ten of that inspired ; and 

 if on leguminous food, they absorb a quantity 

 intermediate between that in the tAvo former 

 cases. 3. The consumption of oxygen is di- 

 rectly proportionate to the surface of the body, 

 and inversely to its bulk, so that a sparrow is 

 found to consume ten times more oxygen in a 

 given time than a fowl. This arises probably 

 from the cooling effect of the greater surface. 

 Lastly, in their winter-sleep, or hybernation, 

 animals in some cases actually increase in weight, 

 though without food, living only upon the air, 

 and appropriating its oxygen and nitrogen. 

 * M. Regnault. 



