8 LITE IN NATURE. 



big the inorganic state. And this it cannot do with- 

 out producing some effect, the force it gives off must 

 operate. What should this force do then? what should 

 be its effects ? What but the " functions ?" 



For the force stored up in the body, like all 

 force, may exist in various forms. Motion, as the 

 rudest nations know, produces heat, and heat con- 

 tinually produces motion. There is a ceaseless 

 round of force-mutation throughout nature, each 

 one generating, or changing into, the other. So 

 the force which enters the plant as heat, or light, 

 &c., and is stored up in its tissues, making them 

 " organic"* this force, transferred from the plant 

 to the animal in digestion, is given out by its muscles 

 in their decomposition, and produces motion : or by 

 its nerves, and constitutes the nervous force. 



In this there is nothing that is not according to 

 known laws. The animal body, so far, answers 

 exactly to a machine such as we ourselves construct. 

 In various mechanical structures, adapted to work 

 in certain ways, we accumulate, or store up, force : 



* As heat, we may say, makes water " gaseous." 



