<?onfidered the uppermoft ftratum, and for a
considerable cliftance prefents more uniformity
; the hills are more regular, and rife
by eafy inclination, forming vales of considerable
extent. The foil above is generally
inclinable to the red clay and vegetable
earth, where it continues unimproved.
A large traCt of country around
Derby, in a high ftate of cultivation, has
led me to the obfervation. In this neighbourhood,
the value of coal is moft con-
fpicuoufly feen in agriculture.
The effects of lime on thefe lands is
tolerably afcertained, but in what manner
it ads, has not perhaps been thoroughly
examined. Incapable as I feel myfelf to investigate
this fubjeCt, yet, if by any means I
could contribute to the examination of one
fo interefting, and of fo great public utility, I
fhould confider myfelf as not doing my
duty, did I omit to mention my ideas.
The
The varieties of limeftone render it highly
neceflary, that its properties and different
characters fhould be more generally known.
Some forts are more proper for the pur-
pofes of agriculture, while others claim the
merit for architecture. Limeftone contain-*
lag manganefe, iron pyrites, and earth of
the magnefian genus, is deftruCtive to vegetation,
according to the proportion it
contains, but thefe fubftances do not render
it unfit for a cement. The lime that
contains the largeft portion of carbon, and
free from metallic fubftances, is confidered
moft proper to ftimulate and increafe vegetation.
Lime on clay lands, probably aCts
as an abforbent, the vitriolic acid, which
iron generally imparts to it, is in part dif-
engaged; by which means a fubftance deftruCtive
to vegetation is deftroyed. Lime alfo
aCts powerfully, by preventing large maffes
of earth from forming by adhefi'on, and
1 2 renders