,308 THE VITAL FUNCTIONS. 



to the order in which their elements are arranged ; 

 an order dependent on the processes to which they 

 have been subjected in the system of each particular 

 vegetable. 



In the animal kingdom we observe these pro- 

 cesses multiplied to a still greater extent ; and the 

 resulting substances are even farther removed from 

 the original condition of unorganized matter. In 

 the first place, the food of animals, instead of being 

 simple, like that of plants, has always undergone 

 previous preparation ; for it has either constituted a 

 portion of some other organized being, or it has 

 been a product of organization ; in each case, there- 

 fore, partaking of that complexity of composition 

 which characterises organized bodies. Still, what- 

 ever may be its qualities when received into the 

 stomach, it is soon converted by the powers of 

 digestion into a milky, or transparent fluid, having 

 nearly the same uniform properties. We have 

 seen that there is scarcely any animal or vegetable 

 substance, however dense its texture, or virulent its 

 qualities, but is capable of affording nourishment 

 to various species of animals. Let us take as an 

 example the elytra of cantharides, which are such 

 active stimulants when applied in powder to the 

 skin in the ordinary mode of blistering : we find 

 that, notwithstanding their highly acrid qualities, 

 they constitute the natural food of several species 

 of insects, which devour them with great avidity; 

 and yet the fluids of these insects, though derived 

 from this pungent food, are perfectly bland, and 

 devoid of all acrimony. Cantharides are also, 

 according to Pallas, the favourite food of the 

 Hedge-hog ; although to other mammalia they are 



