what they are worth. As a
rule, too, such men are good farmers, and endeavor to work their land
thoroughly and keep it clean. When this is the case, there can be little
doubt that we can often use artificial manures to great advantage.

"You say," said the Deacon, who had been looking over the tables while I
was talking, "that mixed mineral manures and 50 lbs. of ammonia give
39-3/4 bushels per acre. Now these mixed mineral manures contain potash,
soda, magnesia, and superphosphate. And I see where superphosphate was
used without any potash, soda, and magnesia, but with the same amount of
ammonia, the yield is nearly 46 bushels per acre. This does not say much
in favor of potash, soda, and magnesia, as manures, for wheat. Again, I
see, on plot 10_b_, 50 lbs. of ammonia, _alone_, gives over 43-1/2
bushels per acre. On plot 11_b_, 50 lbs. ammonia _and_ superphosphate,
give 46-1/2 bushels. Like your father, I am inclined to ask, '_Where can
I get this ammonia?_'"

CHAPTER XXVIII.

LIME AS A MANURE.

These careful, systematic, and long-continued experiments of Lawes and
Gilbert seem to prove that if you have a piece of land well prepared for
wheat, which will produce, without manure, say 15 bushels per acre,
there is no way of making that land produce 30 bushels of wheat per
acre, without directly or indirectly furnishing the soil with a liberal
supply of available nitrogen or ammonia.

"What do you mean by directly or indirectly?" asked the Deacon.

"What I had in my mind," said I, "was the fact that I have seen a good
dressing of lime double the yield of wheat. In such a case I suppose the
lime decomposes the organic matter in the soil, or in some other way
sets free the nitrogen or ammonia already in the soil; or the lime forms
compounds in the soil which attract ammonia from the atmosphere. Be this
as it may, the facts brought out by Mr. Lawes' experiments warrant us in
concluding that the increased growth of wheat was connected in some way
with an increased supply of available nitrogen or ammonia."

My father used great quantities of lime as manure. He drew it a distance
of 13 miles, and usually applied it on land intended for wheat,
spreading it broad-cast, after the land had received its last plowing,
and harrowing it in, a few days or weeks before sowing the wheat.
He rarely applied less than 100 bushels of stone-lime to the
acre--generally 150 bushels. He used to say that a small dose of lime
did