This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1876 Excerpt: ...been noticed that the application of a very small quantity of active nitrogen in the form of nitrate of soda, or of an ammonium salt, produces an effect out of all proportion greater than the amount of nitrogen that was actually added to the land in the manure could of itself produce, while it is a matter of the commonest observation that the application to rich land of any considerable amount of such manure is actually dangerous, because of its liability to excite too rank a growth. An application of 112 lbs. of crude nitrate of soda, containing no more than 16 or 17 lbs. of nitrogen, to an acre of good land, has been known to double the grass crop. But a ton of hay contains some 25 lbs. or more of nitrogen, and a crop of 2J tons would consequently carry off more than 60 lbs. of that element. It would seem, in this case, as if the driblet of active nitrogen added in the manure, must either help to start the crop and make it vigorous enough to avail itself of the stores of less accessible nitrogen that are contained in the soil, or that a certain amount of one of the active forms of nitrogen is needed for the performance of some special physiological work within the plant, while the soil-nitrogen, or the products of its decomposition, may be perfectly competent to do the other kinds of work, or indeed most of the work that is required of that element in the process of building a plant. The latter view would appear to derive some support from the familiar fact that some kinds of plants, such as the cereals, have far more need of the active forms of nitrogen than other plants of a different physiological habit, such as clover and turnips. It agrees, moreover, with certain differences in the behavior of plants towards solutions of nitrates, ammonium salts, and...