22 THE LANDED INTEREST. 



results, one most useful fact has been elicited, 

 that of that mass of dark, strongly-smelling sub- 

 stance called dung, its sole property as a manure 

 depends upon the small quantity of chemical 

 salts and of organic nitrogen which it contains, 

 the bulky organic matter being only useful in 

 making the land work better, and rendering it 

 more capable of absorbing and retaining mois- 

 ture. Beginning in 1844 with wheat, the staff 

 of life in this country, he for eight years concen- 

 trated his attention upon it, dividing his experi- 

 mental field into twenty-two plots, upon two of 

 which no manure has ever been applied, and 

 upon the other twenty a carefully considered 

 variety of manures has been continuously used. 

 In 1852 he commenced a similar series of ex- 

 periments with barley, and in 1869, on a smaller 

 area, with oats. Experiments with leguminous 

 crops had been for a series of years continued, 

 but this species of plant being found, when 

 grown too frequently on the same land, to be 

 peculiarly subject to disease, which no con- 

 ditions of manuring appeared capable of ob- 

 viating, they were discontinued. With regard to 



