NEW HUSBANDRY EXEMPLIFIED. 15 



to adhere clolely to the particles of the foil, 

 and is not eafily feparated from them by any 

 other means than by the roots of plants : all 

 land enriched by the atmofphere continues fo, 

 in different ftat.es; if laid down to pafture in 

 a rich ilate, it will be found rich, when broken 

 up for arable, years afterwards : but, after 

 it is brokm up, it is foon impoverished by a 

 few crops taken from it ; unlefs care is taken, 

 that it be at the fame time recruited with new 

 vegetable food. 



That the vegetable food is fomething dif- 

 tindfc from the earth, not natural to it, but 

 adventitious, is derived elfewhere, and capable 

 of adhering to it, or of being detached from 

 it, in a greater or lefs degreee, has been ob- 

 ferved by fome huibandmen, whereof we have 

 a remarkable inftance in Mr. Lifle's Huiban- 

 dry ; who, fpeaking of the fertility of land 

 being abated by cropping it, fays, that this is 

 perceivable by the colour and appearance of 

 the land. " For," fays he, " this vegetable 

 * balfam, though fo difficult to fay wherein 

 it confifts, yet, it may be averred, is as eafily 

 " feen as underftood: for, though almoft as 

 fubtle as a phantom, yet its marks are 

 " clearly difcovcred by the diligent huiband- 

 **'man, converfant about arable land. We 

 c can eafily perceive, by the different colour 

 " of our land (as it turns up under the 

 plough), whether it has borne one, two, 

 * three, or four crops ; and how, in propor- 



" tion, 



