12 INTRODUCTION. 



others, he must manufacture and produce every thing with 

 his own hands which in the social and civilized state of society, 

 he receives from them : this would so occupy his time and 

 talents that he could only produce the bare necessities of a 

 primitive life: his food must be obtained by hunting, fishing 

 and digging roots, his clothing, the skins of animals, his 

 shelter, a rude hut, and his only beverage" water. 



From this mode of living, also, the earth must soon contain 

 more inhabitants than could subsist on its spontaneous food, 

 and part must die of starvation. 



The art of agriculture has been known and successfully 

 practiced by some of the oriental nations from remote ages. 



The Chinese appear to have a good practical knowledge of 

 soils, and have, by industry and skill in agriculture, sustained 

 a population of an almost incredible number: and, although 

 they are supposed to be but little removed from barbarism, 

 they are said to excel all other nations in the amount of food 

 which they produce from a given space of soil. 



That the ancient Romans had an amount of practical know- 

 ledge equal to most nations of the present day, is evident from 

 the following passages from Virgil's Georgics. Thus in his 

 first Georgic he alludes to the rotation of crops, the art of 

 manuring and burning land. 



" Yet shall thy lands through easier labor rear 

 Fresh crops by changeful produce year by year, 

 If rich manure new life and nurture yield, 

 And ashes renovate the exhausted field. 

 Thus interchanging harvests, earth repair; 

 Nor lands unplowed, meantime no profit bear. 

 Much it avails to burn the sterile lands, 

 And stubble, crackling as the flame expands; 

 Whether earth gain fresh strength or richer food, 

 Or noxious moisture, forced by fire exude; 

 Whether it draw through many an opening vein, 

 Juice to fresh plants that clothe anew the plain, 

 Or brace the pores, that pervious to the day, 

 Felt the prone sun's intolerable ray, 

 To piercing showers the expanded fissure close, 

 And the chill north that blisters as it blows." 



