r, "are worth looking at
and thinking about. Why can not the wheat get as much phosphoric acid
out of the soil as the clover?"

"Because," said the Deacon, "the roots of the clover go down deeper into
the subsoil than the roots of wheat."

"That is a very good reason, so far as it goes," said I, "but does not
include all the facts. I have no sort of doubt, that if I had sown this
land to wheat, and put on 75 lbs. of nitrogen per acre, I should have
got a wheat-crop containing, in grain and straw, 30 lbs. of phosphoric
acid. And so the reason I got 15 bushels of wheat per acre, instead of
40 bushels, is not because the roots of wheat do not go deep enough to
find sufficient soluble phosphoric acid."

"Possibly," said the Doctor, "the nitrogen you apply may render the
phosphoric acid in the soil more soluble."

"That is true," said I; "and this was the answer Liebig gave to Mr.
Lawes. Of which more at some future time. But this answer, like the
Deacon's, does not cover all the facts of the case; for a supply of
soluble phosphoric acid would not, in all probability, give me a large
crop of wheat. I will give you some facts presently bearing on this
point.

"What we want to find out is, why the clover can get so much more
phosphoric acid, potash, and nitrogen, than the wheat, from the same
soil?"

MORE ABOUT CLOVER.

The Deacon seemed to think the Doctor was going to give a scientific
answer to the question. "If the clover _can_ get more nitrogen,
phosphoric acid, and potash, from the same soil than wheat," said he,
"why not accept the fact, and act accordingly? You scientific gentlemen
want to explain everything, and sometimes make confusion worse
confounded. We know that a sheep will grow fat in a pasture where a cow
would starve."

"True," said the Doctor, "and that is because the cow gathers food with
her tongue, and must have the grass long enough for her to get hold of
it; while a sheep picks up the grass with her teeth and gums, and,
consequently, the sheep can eat the grass down into the very ground."

"Very well," said the Deacon; "and how do you know but that the roots of
the clover gather up their food sheep-fashion, while the wheat-roots eat
like a cow?"

"That is not a very scientific way of putting it," said the Doctor; "but
I am inclined to think the Deacon has the right idea."

"Perhaps, then," said I, "we had better let it go at that until we get
more light on the subject. We must conclude