liTTKODUCTIOS'. 11 



and to the atmosphere which constantly surrounds and 

 acts upon them. How the plant grows, — ^the conditions 

 under which it flourishes or suffers detriment, — ^the ma- 

 terials of which it is made, — ^the mode of its construction 

 and organization, — how it feeds upon the soil and air, — 

 how it seBves as food to animals, — how the air, soil, 

 plant, and animal stand related to each other in a per- 

 petual round of the most beautiful and wonderful trans- 

 formations, — ^these are some of the grand questions that 

 come before us ; and they are not less interesting to the 

 philosopher or man of culture, than important to the 

 farmer who depends upon their practical solution for his 

 comfort ; or to the statesman, who regards them in their 

 heai'ings upon the weightiest of political considerations. 



