Does the farmer wish to know what kind of soil is necessary to nourish and mature a plant? Chemistry solves the problem. Does the farmer wish to know how to improve the soil? Let him refer to chemistry. Chemistry will teach the farmer how to analyze the soil; by that means he will learn which of the constituent elements of the plants and soil are constant, and which are changeable. By making an analysis of the soil at different periods, through the process of germination, growth, and maturity, we are enabled to ascertain the amount of excretory elements given out. Bergman tells us that he found, by analysis, in "100 parts of fertile soil, coarse silex 30 parts, silecia 30 parts, carbonate of lime 30 parts:" hence the fertility of the soil diminishes in proportion as one or the other of these elements predominates. Ashes of wheat contain, among other elementary substances, 48 parts of silecia. Now, what farmer could expect to raise a good crop of wheat from a soil destitute of silecious earth, since this earth constitutes a large amount of the earthy part of wheat? There is no barrier to agricultural improvement so effectual as for farmers to continue their old customs purely because their forefathers did so. But prejudices are fast dying away before the rays of intellectual illumination; the farmers are fast seceding from the supposed infallibles of their forefathers, and will soon become "book" as well as practical husbandmen. "Book farming," assisted by practical knowledge, teaches that manures require admixture of milder materials to mitigate their force; for some of them communicate a disgusting or offensive quality to vegetables. They are charged with imparting a biting and acrimonious taste to radishes and turnips. Potatoes and grapes are known to borrow the foul taint of the ground. Millers observe a strong, disagreeable odor in the meal of wheat that grew upon land highly charged with the rotten recrements of cities. Stable dung is known to impart a disagreeable flavor to vegetables. The same effects may be illustrated in the animal kingdom. Ducks are rendered so ill tasted from stuffing down garbage as sometimes to be offensive to the palate when cooked. The quality of pork is known by the food of the swine, and the peculiar flavor of water-fowl is rationally traced to the fish they devour. Thus a portion of the elements of manure and nutrimental matter passes into the living bodies without being entirely subdued. For example, we can alter the color of the cow's milk by mixing madder or saffron in the food; the odor may be influenced by garlic; the flavor may be altered by pine and wormwood; and lastly, the medicinal effect may be influenced.