that:
Phosphoric
Nitrogen. Acid.
10 tons of dry earth before using
contained 63 lbs. 36 lbs.
10 tons of dry earth after being used once
contained 74 " 50 "
10 tons of dry earth after being used twice
contained 84 " 88 "
10 tons of dry earth after being used thrice
contained 102 " 102 "

After looking at the above figures, the Deacon remarked: "You say 10
tons of dry earth before being used in the closet contained 62 lbs. of
nitrogen. How much nitrogen does 10 tons of barn-yard manure contain?"

"That depends a good deal on what food the animals eat. Ten tons of
average fresh manure would contain about 80 lbs. of nitrogen."

"Great are the mysteries of chemistry!" exclaimed the Deacon. "Ten tons
of dry earth contain almost as much nitrogen as 10 tons of barn-yard
manure, and yet you think that nitrogen is the most valuable thing in
manure. What shall we be told next?"

"You will be told, Deacon, that the nitrogen in the soil is in such a
form that the plants can take up only a small portion of it. But if you
will plow such land in the fall, and expose it to the disintegrating
effects of the frost, and plow it again in the spring, and let the sun
and air act upon it, more or less of the organic matter in the soil will
be decomposed, and the nitrogen rendered soluble. And then if you sow
this land to wheat after a good summer-fallow, you will stand a chance
of having a great crop."

This dry earth which Dr. Voelcker analyzed appeared, he says, "to be
ordinary garden soil, containing a considerable portion of clay." After
it had been passed once through the closet, one ton of it was spread on
an acre of grass-land, which produced 2 tons 8 cwt. of hay. In a second
experiment, one ton, once passed through the closet, produced 2 tons 7
cwt. of hay per acre. We are not told how much hay the land produced
without any dressing at all. Still we may infer that this top-dressing
did considerable good. Of one thing, however, there can be no doubt.
This one ton of earth manure contained only 1-1/4 lb. more nitrogen and
1-1/2 lb. more phosphoric acid than a ton of the dry earth itself. Why
then did it prove so valuable as a