130 CHYMISTRY APPLIED TO AGRICULTURE. 



As the estate which T own is very extensive, I have not 

 hesitated to set apart from my regular rotation of crops, 

 about two hundred and fifty acres of land of middling qual- 

 ity, which had every year been manured equally with my 

 best lands, but which had yielded but poor returns. This 

 great extent of land is now laid down to grass, and serves 

 as a pasture for njy cows, oxen, and sheep : each year I 

 break up one fifth part of it, and sow it with oats, rye, or bar- 

 ley, and the following year reestablish it as a grass land. I 

 am convinced that this land would never have repaid me for 

 the expense attendant upon raising from it successive crops 

 of grain, roots, and legumes. 



CHAPTER VII. 



OF THE SUCCESSION OF CROPS. 



A SOIL may be forced, by extreme care, enormous ex- 

 pense, and the use of manure without measure, to produce 

 all sorts of crops ; but it is not in such sort of proceedings 

 ihat the science of agriculture consists. Agriculture ought 

 not to be considered as an object of luxury ; and whenever 

 the produce of agricultural management does not amply 

 repay the care and expense bestowed upon it, the system 

 followed is bad. 



A good agriculturist will, in the first place, make himself 

 acquainted with the nature of his soil, in order to know the 

 kind of plants to which it is best adapted : this knowledge 

 may be easily acquired by an acquaintance with the species 

 of the plants produced upon it spontaneously, or by exper/- 

 ments made upon the land, or upon analogous soiis jn the 

 neighbourhood. 



But however well adapted the soil and climate may be 

 to the cultivation of any particular kind of vegetable, the 

 former soon ceases to be productive, if constantly appro- 

 priated to the culture of plants of the same or analogous 

 species. In order that land may be cultivated success- 

 fully, various kinds of vegetables must be raised upon it 

 in succession, and the rotation must be conducted with 

 intelligence, that none unsuited either to the soil or cli- 

 mate may be introduced. It is the art of varying the 



