I have heard people say a farmer could not make manure unless he kept animals. We might with as much truth say a farmer cannot make ashes unless he keeps stoves; and it would be just as sensible to take a lot of stoves into the woods to make ashes, as it is to keep a lot of animals merely to make manure. You can make the ashes by throwing the wood into a pile, and burning it; and you can make the manure by throwing the material out of which the manure is to be made into a pile, and letting it ferment. On a farm where neither food nor manure of any kind is purchased, the only way to make manure is to _get it out of the land_. “From the land and from the atmosphere,” remarked the Doctor. “Plants get a large portion of the material of which they are composed from the atmosphere.” “Yes,” I replied, “but it is principally carbonaceous matter, which is of little or no value as manure. A small amount of ammonia and nitric acid are also brought to the soil by rains and dews, and a freshly-stirred soil may also sometimes absorb more or less ammonia from the atmosphere; but while this is true, so far as making manure is concerned, we must look to the plant-food existing in the soil itself. “Take such a farm as Mr. Dewey’s, that we have already referred to. No manure or food has been purchased; or at any rate, not one-tenth as much as has been sold, and yet the farm is more productive to-day than when it was first cleared of the forest. He has developed the manure from the stores of latent plant-food previously existing in the soil and this is the way farmers generally make manure.” CHAPTER XI. THE VALUE OF MANURE DEPENDS ON THE FOOD--NOT ON THE ANIMAL. “If,” said I, “you should put a ton of cut straw in a heap, wet it, and let it rot down into manure; and should place in another heap a ton of cut corn-fodder, and in another heap a ton of cut clover-hay, wet them, and let them also rot down into manure; and in another heap a ton of pulped-turnips, and in another heap a ton of corn-meal, and in another heap a ton of bran, and in another a ton of malt-sprouts, and let them be mixed with water, and so treated that they will ferment without loss of ammonia or other valuable plant-food, I think no one will say that all these different heaps of manure will have the same value. And if not, why not?” “Because,” said Charley, “the ton of straw does not contain as much valuable plant-food as the ton of corn-fodder, nor the ton of corn-fodder as much as the ton of clover-hay.” “Now then,” said I, “instead of putting a ton of straw in one heap to rot, and a ton of corn-fodder in another heap, and a ton of clover in another heap, we feed the ton of straw to a cow, and the ton of corn-fodder to another cow, and the ton of clover to another cow, and save _all_ the solid and liquid excrements, will the manure made from the ton of straw be worth as much as the manure made from the ton of corn-fodder or clover-hay?”