Ilence the need of artificial assistance to eke out the means which the domestic supplies provide. Till within the last few years the ordinary plan of doing this was by menus of compost heaps, in which, by the aid of a little farm-yard dung as a ferment, materials less liable to decomposition were induced to rot together: in which, too, the waste products of other processes were economised and turned to use. What a number of things may thus be turned to good account is apparent from the mere list of them :—Animal, vegetable, and mineral substances existing upon the farm ; roots, hedge clippings, and fallen knees ; couch grass, fern leaveq, moss, river• and sea weeds, sods and turf from ditches, lanes, and hedge-rows ; siw-dust, spent hark, and peat, when properly decomposed. Many of these contain nitrogenous ingredients in larger proportion than the straw of grain, and several of them are equally rich in the mineral constitueets of plants. Animal substances, such as carcasses, blood, bones, fat, blubber, waste fish, sprats, and various shell fish, are, in particular place., to be sometimes had abunehmtly. They all contain nitrogen, and so are capable of forming ammonia in larger quantity than our highly valued farm-yard dung. Mineral substances also are available : earth from hedges, scouring., of ditches, hanks, ponds, &c., eonteining a large share of vege table matter, and road-scrapings are also elements, of composts. Many refuse substances of trade and manufactures are also available in this way : woollen rags, shoddy, soapers' waste, soapers' ley, paper waste, glue refuse, and refuse of salt-works, of starch-works, sugar-works, slaughter-houses, cider-mills, gas-works, &c., may thus all be used. Many of them are not fit for use in their natural state ; but in compost with others, and suffered to rot there, they become useful.
Composts, too, are useful as diffusing and diluting stronger appli cations : guano may thus be economised. They exercise a beneficial influence on fertility, in virtue of their mechanical effects upon the soil. Stiff soils may thus be improved by vegetable compcsts, and light soils by heavy composts. Lime, of course, is a chief ingredient in composts, and has been already adverted to. Let us, however, call attention to the labour of making and carting bulky and comparatively poor manures, as composts generally are, in order to defend the greater economy as a general rule of purchasing artificial fertilisers, in order to supplement the deficiency of what may be called the natural supply.
What an immense variety of artificials, so-called, which the farmer has now at his command, is apparent from the following list :— To guano reference has already been made. [Gamic.] It may be applied to almost every crop with advantage, and it is well to mix it with mould for diluting it, or with common salt for preserving it. M. Barral, a well known French agriculturist, "exposed to the air for fifteen days equal weights of guano, and of guano mixed with half its weight of common salt, and he found that pure guano lost per cent. of its nitrogen during that time, while that mixed with salt had lost only 5 per cent." And Mr. Northeote's conclusions are, thatagr icul tural " salt is an energetic absorbent of ammonia, both on account of its chloride of sodium, and on account of the sulphate of lime which it contains ; and that the quantity of lime-salt present especially, most powerfully affects its action in this way. Its agency, however, does not seem to be a very permanent one, though it will collect and retain the ammonia long enough, probably, for agricultural purposes.
When thus mixed with a substance, which at the same time that it fixes more or less the volatile ingredient of guano, does also increase the bulk of the manure, and so enable its 'more even distribution over the land, it should bo applied during, or immediately before the season of most rapid growth ; as, for instance, if for grass, just after a mowing, when the young plants, furnished with a full grown ap paratus of roots are prepared to make rapid use of whatever food for plants is presented to them. For the same reason too, it is best applied
to the wheat crop in spring time over the young plant, rather than before the sowing, whether that is spring or autumn. In that case, some 3 or 4 cwt. per acre of the manure properly prepared is sown broadcast, and hoed or harrowed in, or if, during wet weather, left without a harrowing. For green crops again, as swedes or mangold wurzel, it is more commonly sown broad-cast over the raised drills, between which, the farm-manure is placed, and then covered by the same Witting of the drills which covers the manure. Or if the seed is sown upon the flat, the guano is mixed with a large quantity of ashes, and either sown broad-cast previous to the harrowing which precedes the sowing machine, or it is drilled under the seed by the same machine—a separate set of weighted coulters being used for its con veyance--the effeet being, that the manure is covered by the earth before the seed is deposited above it.
Of all the other artificial fertilisers now available in English agri culture, that which most directly comes in competition with guano is the nitrate of soda, of which it is probable that large supplies may become available, especially from Peru. The nitrates of potash and soda are applied at the rate of about 1 cwt. per acre, and especially on poor lands they wonderfully increase luxuriance of growth in corn crops, and the consequent yield of corn per acre. In several instances 1 cwt. per acre has produced an increase of 12 bushels per acre in the wheat crop, and of 4 or 5 sacks in the oat crop, and though it is especially influential in the case of poor lands, yet that it is also of great service on fertile soils well-managed, is plain from the following statement by Mr. Hope, of Fenton Barns, Haddington :— Ile says in a letter to Mr. Pusey, " I have only applied nitrate for two years to wheat, and that after seeing the account of your own experiment in Mr. Caird:s ' English Agriculture.' In April, 1852, I top-dressed wheat after potatoes ; the soil a dry gravelly loam. At the time the wheat was not very promising in appearance, I sowed on part 1 cwt. nitrate mixed with 1 cwt. salt per imperial acre ; on another portion 3 cwt. Peruvian guano was applied, and a part got nothing. The nitrate of soda soon took the lead, and kept it. A portion of each was threshed separately, when they were found to yield as follows, viz :— "In 1853 I tried the same thing on wheat after beans ; I never, how ever, could detect any difference with the eye, except where the crop got nothing, though in the former year the difference between the two manures could be seen at a glance; and having cut the crop with a reaping machine, which rather intermixed the lots, I was prevented threshing them separately. I have bought 5 tons of nitrate for next year and mean to apply a portion to potatoes." The only reason why nitrate of soda is preferred to nitrate of potash depends upon the greater cost of the latter. The proper time for sow ing either is during the period of rapid growth ; they, like all soluble manures, are immediately spread throughout the soil by the showers, and of course are liable to waste unless the plant to which they are applied be ready to use them at once. Both of these salts are liable to adulteration, and common salt is the chief substance used for this pur pose; its presence is detected on throwing any of it on some hot coals by the crepitating sound which follows. Pure nitre burns the coal up without any of these little explosions.