"'What would be the effect upon the farming interest to push the soil up to something near its full capacity?'" "But what can he mean," said the mother. "How can anyone do better than we have done? We change our crops, and sow clover with the oats, and return as much as we can to the land. But let me hear further what Lincoln said:" "Yes, Mother, this is what he said: "'Unquestionably it will take more labor to produce fifty bushels of wheat from an acre than it will to produce ten bushels from the same acre; but will it take more labor to produce fifty bushels from one acre than from five? Unquestionably thorough cultivation will require more labor to the acre; but will it require more to the bushel? If it should require just as much to the bushel, there are some probable, and several certain, advantages in favor of the thorough practice. It is probable it would develop those unknown causes which of late years have cut down our crops below their former average. It is almost certain, I think, that by deeper plowing, analysis of the soils, experiments with manures and varieties of seeds, observance of seasons, and the like, these 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: