oviso in
your act. Here I have offered for years to allow the upper
proprietors to make any alteration they liked in the weir,
provided such alterations did not affect the milling power, the
stability of the weir, or my legal title to the weir as existing
at present. And my legal adviser tells me that any alteration made
in the weir without a guarantee from the upper proprietors would
very probably deprive me of my present title.

* * * * *

LETTERS ON AGRICULTURAL SUBJECTS.

* * * * *

ON THE CULTIVATION OF WHEAT ON THE SAME LAND IN SUCCESSIVE YEARS.

_To The Editor of the "Manchester Guardian."_

CLITHEROE, October 5th, 1843.

SIR,--I PROMISED to send you some details of my attempt to grow
wheat on the same soil year after year. These I now forward, and
hope they may prove interesting. I was led into these experiments
by reading Liebig's book on the "Chemistry of Agriculture;" for,
assuming his theory to be true, it appeared to me to be quite
possible to grow wheat on the same land year after year; as,
according to that theory, the carbon, oxygen, and hydrogen, which
constitute the great bulk of all cereal crops (both grain and
straw), are supplied in abundance from the soil and atmosphere (or
perhaps, to speak more correctly, from the latter), and we have
only to supply those inorganic substances, which, however
numerous, form but a small part of the whole weight of the crop.
With the view of testing this theory, and hoping that I might be
able to find out what were the elements which built up and
cemented the carbon, oxygen, and hydrogen together--or, in other
words, which constituted fertility--I begun, in the autumn of
1841, to experiment on a field which had been exhausted by a
succession of crops, and which had just been cleared of one of
oats. I chose an exhausted field in preference to any other, as
the only one in which I could test the truth of the theory. It was
very foul, being full of couch grass and weeds of all kinds. It
was ploughed up and hastily picked over, for the season was so
unfavourable for cleaning the land (from the great quantity of
rain that fell) that I was almost induced to abandon the
experiment. Previously to sowing the seed, one-fourth of the field
was manured with a compost of night-soil and coal-ashes, at the
rate of forty tons to the customary acre (7840 yards); the
remaining three-fourths having the seed put in without any manure
whatever. The winter was very unfavourab