'(o OF THE FOOD OF PLANTS. Part L 



wheat every year off the fame land. All that is required to that end 

 is, to plow oftener ; to divide the particles of the earth fufficientlv ; 

 to put the plants in condition to feek their necefiary food; to hinder 

 weeds from robbing the plants cultivated ; and laflly, to raife no 

 more plants in a field, than it can nouriihi properly. All thefe ad- 

 vantages are obtained by the new Hufbandry. 



CHAP. V. 



Of the dijlribution of the Food of Plants within the Rarth. 



THE food of plants, of whatfoever nature it be, feems to be 

 difperfed throughout every part of the earth : but it would 

 lie ufelefs there, if plants could not get at it. They muft be able 

 to extend their roots between the particles of the earth. Too firiff 

 a foil, that is to fay, a foil of v/hich the particles lie too clofe to- 

 gether, hinders their extenfion. It is therefore neceffary that there 

 fliould be Ipaces between thofe particles, through which the roots 

 may extend themfelves. Moft foils have, by nature, internal pores ; 

 but they are, in general, either too few in number ; or not properly 

 fitted to the roots. 



If they are too few, there will often be a want of communication 

 betwixt one pore and another ; and the roots thereby impeded in 

 their progrefs, will not be able to find the food neceffary for the 

 plant. This is the defeat of too ftrong lands. 



If the interfaces are too great, the roots, pafling through them 

 without fcarcely touching the earth, will draw little or no alfiftance 

 from it : this is the defeift of light lands. 



Both thefe defefts may be remedied by proper culture : for the 

 earth contains fo great a quantity of nutritive juices, that there is no 

 danger of exhaufting them. The only point is, to enable the roots 

 to reap the beqefit of them. It is ftill lefs to be feared, that this . 

 nourilhing juice may diffipate or wafte itfelf. Experience demon- 

 ftrates that it cannot : for let earth be dried to ever fo great a degree, 

 let it be pulverifed, and expofed to the fun, rain, and froff, it will 

 only become the more fertile for it. 



It is certain, that water fliould diffolve the particles deftined for the 

 food of plants ; and that this vehicle is almoft entirely dilTipated by 

 tranfpiration, after it has dcpofited in plants what is to be converted 

 into their fubftances. But when water evaporates from the earth, 

 without paffmg through plants, it does not carry the nutritive parts 

 I off 



