Chap. VI. O F T I L L A G E. 13 



languiOi. But when thole lands ihall have been divided by tillage, 

 when their particles fhall have been fo feparated, that roots are at 

 liberty to extend thcmfelves and traverle all thofe fmall fpices, they 

 will be able to fupply the plants with their neceflary food, and they 

 will thrive apace. 



Tillage is equally beneficial to light lands ; but for a contrary 

 reafon. The fault of thefe lands, is their having too great fpaces 

 between their particles ; and as moft of thofe fpaces have no com- 

 munication one with another, the roots traverfmg the great cavities 

 without touching the particles of the earth, draw confequently no 

 nourhhment from it. But when the particles have been broken by 

 repeated plowings, the lefTer intervals are multiplied at the expence 

 of the greater : the roots have liberty to extend themfelves, and they 

 glide in, as it were, between the particles, meeting with a certain 

 refiftance which is necelTary to their taking in their nutritive juice 

 which the earth contains. 



Mr. Evelyn, quoting Sir Hugh Piatt, fays, " that if you take a 

 " certain quantity of even the moft barren earth you can find, re- 

 " duce it to a fine powder, and expofe it for a year to the vicilTitudes 

 *' and changes of the feafons, and influences of the heavens, it will 

 " acquire fuch a genuine and mafculine pregnancy, within that 

 " period, as to be able to receive an exotic plant from the fartheft 

 " Indies, and to caufe all vegetables to profper in the moft exalted 

 " degree, and to bear their fruit as kindly with us, as they do in 

 " their natural climates." We are to fuppofe thofe exotics to have 

 their due degrees of heat and moifture given them. To what ihall 

 we afcribe this great fertility .? Moft probably it is owing chiefly to 

 the great divifion of the particles of the earth, and the multiplication 

 of their furfaces. " By this toil, {yiz. pulverizing the earth) adds 

 he, 'tis found, that a foil may be fo ftrangely altered from its former 

 «♦ nature, as to render the hadh, and moft uncivil clay, obfequious 

 " to the hufhandman, and to bring forth roots and plants, which 

 " otherwife require the lighteft and holloweft moulds." 



What Air. Evelyn fays, does not, however, hold good with re- 

 fpedl to every kind of earth : for M. Duhamel pulverifed ftift" clay, 

 and fifted it through a pretty fine fieve ; notwithftanding which, 

 after it was well foaked with water, it became as clofe and compadl 

 as it was before he pounded and fifted it. 



From this experiment it may be inferred, that dung is more 

 neceflary for clay lands than for any other, becaufe it prevents the 



particles 



