ARTIFICIAL AND BARNYARD MANURES. rht lr Coir! ;u,iitio!i .ami Valuation as K ntri! by u .svlc-iti'.ic-Agrimltnlix'. The functions of manures, as bnofiv slated by a professor of the Umvorsuv of North Wr.les, who has conducted extensive mauurial experiments, are: 1. In many oa-es the improvement of the mechanical and physical condition condi-tion an-1, liie texture of the soil to which the ww are applied. Thus lime, v he'U:; ; to sour land, decomposes, decom-poses, and ;.!. oat" renders harmless, the sour or .....ic i.U whoso presence in the soil is c.ra.:e of t ho sour or acid condition of tue lard. When farmvard manure -is applied to laud the texture and physical coudition of the soil is much improved by the organic matter of which this manure is largely composed. com-posed. 9. In 'many cases manures act on plant food already present in the soil and convert this plant food into such a coudition that it can be absorbed by the roots of plants. The manurial value of lime is due principally to the action of this manure on the food of plants already al-ready present in the soil. 3. The most important function of manures is to supply plant food necessary for' the growth of crops which is deficient in the soil. Tho ' necessary constituents of plant food that are generally deficient in soils are nitrogen, phosphoric acid and potash. Nitrogen' occurs in manures as nitrates, ni-trates, e. g., nitrates of soda; ammonia salts, e. g., sulphate of ammonia; organic or-ganic nitrogen, e. g., dried blood. Nitrogen Ni-trogen as nitrates is immediately available availa-ble as plant food. Nitrogen as ammonia salts soon becomes available. Nitrogen as organic nitrogen is much more slowly available. Phosphoric acid, combined with lime, is generally present iu manures as insoluble insol-uble phosphate of lime, e. g., bone meal and basic -slag; soluble phosphate of lime, -e. g., -superphosphates. Insoluble phosphate of lime is converted into soluble, solu-ble, or superphosphate, by treating it with "sulphuric acid. Soluble phosphates are generally more active than insoluble phosphate's in promoting plant growth. Potash is the valuable .ingredient iu -kaiuit and muriate of potash. Potash has generally a- better effect on light than on -heavy ' soils.. Superphosphate and nitrate of soda should not be mixed, or if mixed linst be sown immediately. This also applies to the mixing of basic slag and sulphate of ammonia. Artificial manures should be pur- chased on a guaranteed analysis, and tho sourco from winch the fertilizing ingredients in-gredients of the mnnuro are derived should bo siat'vl. This nrecautioh is es- pecially r..-c?--:ivy in purchasing bone or mixed mann ; s. Tho percentage of irjtrof-e: ": i a vr.-.-ri'-o should be stated in its eiinT : Ih..i Kc a'miciiia, that ofiii-solublo ofiii-solublo ph;-' horic acid as phosphate of lime, tvm'-ila pho-phoric acid as phosphate phos-phate of .;. r.;u that of potash salts in their f .hvah :;r of potash. Artificial uianuv: ; j r; vahiud according to the quanti ' '. nit ven, r ubh phosphate of lim;-. J... olnbhr jnwf; "wio of lime and potash they contain. Farmyard lna-inro contains all the ingredients in-gredients of plant food. This manure is exceedingly variable in quality, as tho quality varies with the nature of tho. food given to (he animal, the nature and amount of tho litter used, tho method by which the manure is produced and its treatment from the time of production produc-tion until it i3 ivpplied to the land.