f 290 ] 
6. What reafons do you affign for foils tiring of one 
fpecies of plant, and yet producing another fpecies 
vigorou/ly? 
As this circumftance is not general in gardening, © 
I fhould fuppofe it to arife from fome local circum- 
tances of fituatiou and temperature, or from fome 
defeé in the quantity of the foil, or infufliciency of | 
movement. See query 3d. 
7- Of what is a foil deprived, when it is faid to 
be exhaufted? ~ 
OF no fenfible chemical quality whatever inherent 
in the foil. Suppofing a thin foil to be burn-baked, 
when firft broken up, and by a courfe of crops to be 
exhautted, let a good drefling of vegetable athes be 
given it, and I fhould expeé it capable of a fimilar 
courfe. The alkaline cbtained by the operation at 
firft may be totally loft, but that not being origi- 
nally in the foil, the foil is, by the crops it bears, 
reduced to its original ftate, and may be fupplied by 
a frefh quantity. In various inftances, analogy may 
be preferved, though circumftances may vary; as 
fome lands may require a calcareous, an acidulous, 
or ammoniacal manure, inftead of an alkaline. Ad- 
ventitious qualities may be communicated, exhaufted, 
and reftored, the inherent character remaining. 
8. What do you fuppofe to be the compofition of the 
mofe fertile foil? 
‘True original earth—that produced by a compleat 
putrefaction of animal and vegetable fubftances. 
9. Do 
