A gentleman after making sundry careful experiments with plaster and carbonate of ammonia, thus expresses his conclusions--"These experiments prove to me that no matter in what state, (whether _wet_, _moist_, or _dry_,) plaster is presented to guano, or any other manure from which the carbonate of ammonia is escaping, it must retain a certain amount of ammonia that would otherwise be lost in the atmosphere." The editor of the American Farmer says--"If the soil be poor, and it be desired to permanently improve it, at least four hundred pounds of guano, without respect to the fixer used, should be spread _broadcast_, on every acre of it, and plowed in to the full depth of the furrow. If the land be in moderate heart, three hundred pounds will be enough per acre. Where the soil may be good, two hundred will be sufficient. These quantities, as the reader will observe, have relation to broadcast applications, as all should be where general improvement is contemplated; if compelled to confine his experiments on corn to applications in the hill, a form of manuring, we have ever disapproved, two hundred pounds, or even one hundred of guano, will manure an acre, mixed with a bushel of plaster, five bushels of slaked ashes, and a double horse cart of wood mould more effective than ten loads of manure applied in the hill." Yes, as has been proved by careful experiment made in England, more than fourteen tons of manure. The editor also says, what we have so often repeated--"We hold these to be agricultural truths--that guano is most beneficially applied, when ploughed in as spread on the the earth, never less than four inches deep--and better, for permanent effect, to be ploughed in deeper, say six to eight inches--where it may be desirable only to bury it four inches deep, the land should be previously ploughed as deep as the furrow can be turned up, and the guano applied at a second ploughing--that all top-dressings with guano are wasteful, inasmuch, as from the volatile nature of the more active parts of the manure, great loss must inevitably result from all such applications, and because, more moisture than is to be found on the surface, is necessary to excite, and carry on, that healthful progressive state of decomposition, which is required to render guano most available for present production and future improvement.