just what you think
on this subject."

"In brief," said I, "my opinion is this. We need ammonia for wheat. But
though ammonia-salts and nitrate of soda can often be used with decided
profit, yet I feel sure that we can get ammonia or nitrogen at a less
cost per lb. by buying bran, malt-roots, cotton-seed cake, and other
foods, and using them for the double purpose of feeding stock and making
manure."

"I admit that such is the case," said the Doctor, "but here is a plot of
land that has now had 14 tons of manure every year for seven years, and
yet there is a plot along side, dressed with ammonia-salts furnishing
less than half the ammonia contained in the 14 tons of manure, that
produces a better yield of wheat."

"That," said I, "is simply because the nitrogen in the manure is not in
an available condition. And the practical question is, how to make the
nitrogen in our manure more immediately available. It is one of the most
important questions which agricultural science is called upon to answer.
Until we get more light, I feel sure in saying that one of the best
methods is, to feed our animals on richer and more easily digested
food."

The following table gives the results of the _eighth_ season of 1850-51.

Experiments at Rothamsted on the Growth of Wheat, Year After Year,
on the Same Land.

Table VIII.--Manures and Produce; 8th Season, 1850-51. Manures and
Seed (Red Cluster), Sown Autumn, 1850.

Manures
FM Farm-yard Manure.
WSC Cut Wheat-straw and Chaff.
CS Common Salt.
SP Sulphate of Potass.
S-A Soda-ash.
SMg Sulphate of Magnesia.
B-A Bone-ash.
SAc Sulphuric Acid. (Sp. gr. 1.7)
MAc Muriatic Acid.
SAm Sulphate of Ammonia.
MAm Muriate of Ammonia.
RC Rape-cake.

----+---------------------------------------------------------------+
| |
| Manures per Acre. |
P +-----+----+------+----+----+----+---------------+----+----+----+
l | | | | | | | Superphosphate| | | |
o | | | | | | | of Lime. | | | |
t | | | | | | +----+----+-----+ | | |
s | FM |WSC | CS | SP |S-A |SMg |B-A |SAc | MAc |SAm |MAm | RC |
----+-----+----+------+----+----+----+----+----+-----+----+----+----+
|Tons.|lbs.| lbs. |lbs.|lbs.|lbs.|lbs.|lbs.|lbs. |lbs.|lbs.|