60 



INORGANIC MANURES, CONSIDERED 



classed according to the kind of animal to which the litter is supplied ; and 

 hence we have horse -dung, cow-dung, the dung of swine, sheep, rabbits, 

 poultry, &c. All these manures require to be brought into a state of active 

 fermentation, and reduced to a soft easily separated mass, before being 

 applied to the soil. This is effected by throwing them into heaps, and occa- 

 sionally turning these heaps till the manure becomes of a proper consistence. 



191. In horticulture, advantage is generally taken of the heat produced 

 by manures of this kind, in forming hotbeds, and in supplying heat to pits by 

 what are called linings, but which are properly casings, of dung placed round 

 a bed of dung, tan, or soil, supported by walls of open brickwork. The dung 

 so placed can be taken away at pleasure, and applied to the soil when it has 

 undergone a proper degree of fermentation; whereas, the dung of which hot- 

 beds is formed cannot be removed without destroying the bed and the crop 

 on it ; and hence it is generally kept till the fermenting process is carried 

 much farther than is necessary, and often so far as to be injurious. Hence, 

 in gardens, wherever economy of manure is an object, common hotbeds ought 

 never to be made use of, but recourse had to exterior casings, such as those 

 already mentioned, or to other modes of heating. 



192. In many suburban villas, almost as much manure is lost as would 

 suffice for enriching the kitchen-garden, and producing vegetables for the 

 whole family. To save every particle of fluid or solid matter capable of 

 becoming manure, the first step is to construct two or more large tanks for 

 the liquid manure, and to form a system of tubes or guttei's for conve3'ing to 

 these tanks all the soapsuds and other liquid refuse matters furnished b}'- the 

 mansion and offices, including the stables, unless they are at a distance. 

 Similar tanks should be formed adjoining every cottage and dwelling be- 

 longing to the villa ; such as the gardener's house, gatekeeper's lodge, and 

 also in the back-sheds and in the frame and reserve ground of the kitchen- 

 garden. In short, no water ought to be allowed to escape from the manure 

 tanks but such as is perfectly pure ; for all dirty water, with or without 

 excrementitious matters, will ferment in a degree of heat not much greater 

 than that of the subsoil, even in winter ; and all fermented liquids contain 

 one or more of the constitutent elements of plants. Tlie second step to be 

 taken with a view to saving manure is, to form a vegetable rubbish heap, on 

 which all waste parts of plants and the remains of all crops, including mown 

 grass when not otherwise used, clippings of hedges, summer prunings of 

 trees, &c., are to be thrown as collected, left to ferment, and turned over 

 occasionally. To this heap, lime, dung, or rich earth may be added, and 

 the whole frequently turned over and well mixed. The third step is, to 

 collect the cleanings of ponds, wells, ditches, hedge-banks, and similar earthy 

 matters, and mix them with quicklime, turning the heap occasionally, as 

 directed in the next section. 



Sect. II. — Inorganic Manures, 



193. Inorganic or mineral manures are chiefly, lime in a state of chalk 

 or carbonate, gypsum or sulphate, marl in which carbonate of lime is mixed 

 with clay, saltpetre, kelp or mineral alkali, and common salt. The organic 

 manures, as we have seen, act by supplying plants with the elements of which 

 they are constituted, viz., carbon, oxygen, hydrogen, and azote or nitrogen ; 

 but the mineral manures contain none of these elements, and hence, accord 

 ing to most agricultural chemists, they must act beneficiallj^ on some other 



