FUNCTION OF PLANTS. 



367 



carbon and give out the oxygen of carbonic 

 ac id thus incontestably proving that their 

 function is to purify the air of this gas, and to 

 restore it to the element oxygen. 



These grass-covered fields, and those leaf- 

 crowned forests, are not the mere ornaments of 

 the scene we contemplate. They do not flourish 

 for nought, or live in vain. The pure air which 

 lightly floats along the meadow, and softly 

 whispers the wood-leaves to sleep, parts not 

 with them as it finds them. It comes bearing a 

 deleterious ingredient ; it departs leaving it in 

 some degree behind, and bearing away a health- 

 ful exchange of a fresh supply of oxygen. Thus 

 in beautiful connexion are plants nourished and 



