n of the field which produced
sixty-two bushels per acre (including the guano and the additional
quantity of lime used), was at the rate of 81s. per statute acre.
Deducting the cost of the nitrate of soda, the utility of which,
under the circumstances, I am inclined to doubt, it would have
been 63s. 6d. I consider these to be very favourable results, and
as offering strong inducements to continue the experiment. I have
accordingly had the land ploughed up and cleaned; and it was again
sowed with wheat on the 9th inst. Having detailed the general
results of the experiment, I beg to offer the following remarks
upon some points in it, which seem to me to require a little
elucidation. I consider the success of this experiment to be in a
great measure owing to the use of soluble silica and magnesia;
because, although there is an abundance of silica in the soil, my
first crop showed very miserable results, the grain being ill-fed
and poor, and the straw soft and discoloured, although the year
1842 was, in this district, very favourable for wheat, the month
of August being singularly fine and warm; but when I combined the
nitrate of soda with sulphate of magnesia, as in experiment No. 1
in 1843, but still more so when I combined it with the silicate of
soda, as in No. 3 of that year, the straw became as strong, firm,
and bright as need be desired; and this year when both these salts
are combined with nitrate of soda, common salt, and gypsum, I have
not only good and bright straw, but also an abundant crop of wheat.

With respect to the lime used, it may be as well to state that the
field had not been limed for many years, and although in a
limestone district, showed a deficiency of lime on analysis. The
soil is a strong loam, on a brick clay subsoil, in which there is
little or no lime, although the stony clays, which form the
subsoil in a great part of the district, abound in it, containing
from twenty to thirty per cent. of carbonate of lime. I had always
believed that lime was used in great excess in this neighbourhood,
and had, in fact, an idea that its good qualities were overrated,
inasmuch as it does not enter into the composition of the plant,
except in very minute proportion; but last winter I saw a paper
(by Mr. Briggs of Overton) on the possibility of growing wheat on
the same land year after year, in which the utility of lime in
preventing rust was incidentally touched upon. I also saw Liebig's
letters explaining