^ AURICCLTURAL ESSAYS. 



Food of Vegetables, and the Manner in which it i% 



COMMUNICATED TO THE PlaNT. 



Vegetables are probably the most numerous class of bodies 

 which belong to our globe ; more than forty thousand of tho 

 species having already been discovered, and additions are con- 

 tinually making to the number. It has been shown in a former 

 essay, that no plant which we cultivate can be brought to ma- 

 turity, without the nourishment derived from some kind of veg-- 

 etable manure. If, therefore, we would ascertain what kind of 

 manure is best adapted to the different plants, ana the best 

 mode ot applying it, we must have some knowledge of the pro- 

 cess by which the seed, after it is committed to the earth, ger- 

 minates and progresses towards perfection. It is well known 

 by all who cultivate the earth, that seeds of any kind will not 

 germinate without a certain degree of heat and moisture. But 

 we are indebted to chemists for the discovery that seeds will 

 not germinate, unless atmospheric air, or eome air havino- the 

 same properties, have access to it.* '^ 



It is probable, for this reason, that seeds will not germinate 

 at a certa, depth below the surface of the earth ; and for this 

 reason, the first growth of the plant is often retarded by bury- 

 mg the seed too deep. Is not this fact confirmed by the ob- 

 servation, that the plant of any seed which we commit to the 

 earth, has a more healthy appearance, and grows with more 

 vig-or, the sooner it makes its appearance above the surface 

 alter it begins to germinate. As the progress of the root is 

 dowuvvard, no injury will be likely to happen to it in seasons of 

 common moisture, from its lying too near the surface of the 

 soil; and by springing from the seed, which is buried no 

 deeper than is necessary to germinate, it will be more likely to 

 derive support and efficacy from the noarishmonL furnished 

 trom manure, if properly applied. That the farmer may pre- 

 pare and upply hu manure in the most judicious and efficacious 



*Oa (his suHfict Mr. Davy remark. . fhal in all rases ortill3«^e, 

 the seed should be sowo so as to be fully exposed to the infli.Pnco 

 ofthe air; and one cause of the nnproductivenes? of cold, riavey 

 adhesive soils, is, that tlie seed is r>oated w,fh matt-r imper.Hra- 

 ble to H.r. That in saudy soils the air is ahvavs s.ifficiently pene- 

 trable bv the atmosphtre; but in cl:ivfy sails.' there can scarcely 

 bn too o-reat a ninchanical division of onrfs in Ine proces«o' tillao-e- 

 and sepd not f,,lly «nnp!ivd with air, always produces a weak a"nd 

 d.neased pla.it. gee his Oeiacnls of Agricultural Chemistry, 

 page 191, 192. ° " 



