MANURE, ARTIFICIAL 211 



manures, has led some agricultural writers to describe them under natural manures. 

 Again, others apply the term artificial only to compound saline manuring mixtures, 

 such as wheat- and grass-manures, or to manures the preparation of which necessitates 

 a certain acquaintance with chemical principles and the use of chemical agents. All 

 this confusion can be avoided entirely, if manures, instead of being divided into 

 natural and artificial, were separated into home-made manures, that is, manures pro- 

 duced from the natural resources of the farm, and into imported manures, that is, 

 fertilisers which are introduced on the farm from foreign sources. 



The term ' artificial,' more appropriately, is given to all simple or compound 

 fertilisers in the production of which human art has been instrumental. In this signi- 

 fication we shall use the term ' artificial manure.' 



Not many years ago farmyard manure was universally considered the only efficient 

 fertiliser to restore the fertility of land, impaired by a succession of crops. Recent 

 agricultural experience, however, has shown that, in a great measure, artificial 

 manures may be employed with advantage instead of yard manure, nay, that in several 

 respects artificial manures are preferable to ordinary dung. Indeed, the present 

 advanced state of British agriculture is intimately connected with the success with 

 which artificial manures have been introduced into the ordinary routine on the farm. 



The variety of artificials in present use amongst English farmers is very great. 

 Some, like well prepared samples of superphosphate, are unquestionably manures 

 distinguished for high fertilising properties ; others are less efficacious, or of a doubt- 

 ful character ; and not a few hardly repay the cost of carriage beyond a distance of 10 

 miles. The fact that in almost every market-town artificial manures are sold, which, 

 if not altogether worthless, offer, to say the least, no profitable investment to the 

 occupier of land, shows plainly that the principles which ought to regulate the manu- 

 facture of artificial manures are not so generally understood as it is desirable they 

 should be. In comparison with other branches of industrial art, the manufacture of 

 manures is comparatively simple, and involves no very expensive machinery beyond 

 steam-power for the pulverisation of the raw materials ; nor does it necessitate exten- 

 sive practical experience, or the possession of a large stock of chemical knowledge, on 

 the part of the manufacturer. The limits of this article preclude the detailed de- 

 scription of all the artificial manures that find their way at present into the manure 

 market ; nor does it appear to us necessary to mention in detail the various propor- 

 tions in which the numerous refuse materials used by manure-makers may be blended 

 together into efficacious fertilisers ; for a manufacturer who is thoroughly acquainted 

 with the nature of artificial manures, and the legitimate uses to which they ought to 

 be applied, will find little or no difficulty when working up into artificial manures the 

 raw materials or refuse matters for the acquirement of which a particular locality 

 may offer peculiar advantages. A right conception of the relative commercial and 

 agricultural value of the different constituents that enter into the composition of 

 manures is the chief desideratum for the manufacturer of artificial manure. We 

 therefore propose to refer, in the following pages, briefly to the more important prin- 

 ciples which ought to be kept steadily in view in establishments erected for the supply 

 of artificial fertilisers. 



The high esteem in which good farmyard manure is held by practical men, its uni- 

 formly beneficial effect upon almost every kind of crop, and the economical advantages 

 with which it is usually applied to the land, have induced many to regard farmyard 

 manure as the model which the manufacturer of artificial manure should endeavour 

 to imitate. But this proposition is wrong in principle, as will be shown presently, 

 and its adoption in manure-works has led to disappointment and ruin. It would bo 

 foreign to our object to give in this place a full account of the peculiar merits that 

 belong to yard manure, and to compare them with those exhibited by artificial 

 manures. Each has its peculiar merits and disadvantages, upon which we need not 

 dwell in this article. It will help us, however, in properly comprehending what is 

 really required in a good artificial manure, if we inquire briefly into the composition 

 of good yard manure. We therefore subjoin an analysis, made some time ago by 

 Dr. Voelcker, of well-rotted farmyard manure (see next page) : 



Farmyard manure contains all the constituents which our cultivated crops require 

 to come to perfection, and is suited for every description of agricultural produce. As 

 far as the inorganic fertilising substances are concerned, we find in farmyard manure 

 potash, soda, lime, magnesia, oxide of iron, phosphoric acid, sulphuric acid, hydro- 

 chloric and carbonic acid ; in short, all the minerals that are found in the ashes of 

 ngricultural crops. 



Of organic fertilising substances, we find in farmyard manure some which are 

 readily soluble in water, and containing a large portion of nitrogen; and others 

 insoluble in water, and containing, comparatively speaking, a small proportion of 

 nitrogen. The former readilv yield ammonia, the latter principally give rise to 



