causes would be discovered and remedied. It is certain that thorough
cultivation would spare half, or more than half, the cost of land,
simply because the same produce would be got from half, or from less
than half, the quantity of land. This proposition is self-evident,
and can be made no plainer by repetitions or illustrations. The cost
of land is a great item, even in new countries, and it constantly
grows greater and greater, in comparison with other items, as the
country grows older.'"

Percy paused and said: "If I understand correctly these words of
Lincoln, the land need not become poor. But I do not know why land
becomes poor. I do not know what the soil contains, nor do I know
what corn is made of. We plow the ground and plant the seed and
cultivate and harvest the crop, but I do not know what the corn
crop, or any crop, takes from the soil. I want to learn how to
analyze the soil and crop and to find out, if possible, why soils
become poor, in order, as Lincoln suggests, that the cause may be
discovered and remedied."

"It may be that the college professors could teach you in that way,"
said the mother, "but you know the farm life is so full of work and
so empty of mental culture."

"I used to think so too," said Percy, "but I fear we have worked too
much with our hands and too little with our minds; that we have done
much work in blindness as to the actual causes that control our crop
yields; and that we have not found the mental culture that may be
found in the farm life. Let me read again. These are Lincolns words:

"'No other human occupation opens so wide a field for the profitable