136 EXPERIMENTS OF JETHRO TULL. 



that manure was superfluous. By this pulveriza- 

 tion he raised several successive crops of wheat 

 upon the same land, while his neighbors were com- 

 pelled to resort to a rotation of crops. Considering 

 the state of agricultural science at the period in 

 which he lived, and the numerous obstacles which 

 he surmounted in popular prejudice, and his own 

 enfeebled health, he is certainly entitled to great 

 praise. In his " New Husbandry," he says : " It is 

 without dispute that one cubical foot of this minute 

 powder may have more internal superfices than a 

 thousand feet of the same soil tilled in the common 

 manner ; and I believe no two arable earths in the 

 world do exceed one another in their natural fer- 

 tility twenty times ; that is, one cubic foot of the 

 richest is not able to produce an equal quantity of 

 vegetables, ccsteris partibiis, as twenty cubic feet of 

 the poorest : therefore, it is not strange that the 

 poorest, when by pulverizing it has obtained one 

 hundred times the internal superfices of the rich, 

 untilled land, should exceed it in fertility. Or, if 

 a foot of the poorest were made to have twenty 

 times the superfices of a foot of such rich land, the I 

 poorest might produce an equal quantity of vege- 

 tables with the rich. 



" There is another manifest advantajire when a 

 soil has been finely pulverized, — the roots are 

 supplied with nourishment nearer to them on all 

 sides than they could be if the soil was coarser, as 



