AGRICULTURE. 



be wetted with dilute sulphuric acid, so as to 

 render its phosphates more soluble and its car- 

 bonutes less volatile ; or, what is still better, it 

 may form part of a well-made superphosphate 

 of lime. The best of these is the nitrogenized 

 superphosphate of lime, made by the admix- 

 ture of 100 pounds of calcined bones, 56 pounds 

 of sulphuric acid, 36 pounds of Peruvian guano, 

 and 20 pounds of sulphate of ammonia, to 

 which may be added an equal weight of dried 

 blood, the whole to be thoroughly ground to- 

 gether. Six hundred pounds of this mixture 

 will fully represent twenty -five cords of well- 

 rotted farm and stable manure. 



Lime. Lime, as it is generally used, cannot be 

 viewed as an immediate or direct food for plants ; 

 that which is contained in decaying organisms, or 

 as resulting from the ashes of wood and other 

 substances, when applied to the soil, is readily as- 

 similated by plants ; but the more crude kinds 

 of lime, such as are made by the burning of the 

 ordinary limestones, have their first action 

 friendly to vegetable growth in their power to 

 decompose all organic matter, and thus cause it 

 to give up its inorganic constituents ; in addition 

 to which, it acts upon the inorganic constitu- 

 ents of the soil itself, forming silicate of lime ; 

 and by removing portions of the surface of par- 

 ticles, presents new surfaces for other chemical 

 action and continued development. 



Lime, when combined with salt, so as to form 

 chloride of lime and carbonate of soda, before 

 its use in soils, becomes materially more active 

 and in a condition to be rapidly appropriated. 

 Three bushels of lime, slaked with a solution 

 of one bushel of salt, and then exposed to the 

 atmosphere until the chlorine of the salt com- 

 bines with the lime, forming chloride of lime, 

 and setting free the soda, permitting it to com- 

 bine with carbonic acid from the atmosphere, 

 becoming carbonate of soda, form an admirable 

 fertilizer. Four bushels of this mixture, suffi- 

 ciently old for all the chemical changes to have 

 occurred, if mixed with a cord of any cheap 

 organic matter, such as swamp muck, woods- 

 earth, etc., will decompose it to a powder in a 

 very short space of time. It is therefore a val- 

 uable auxiliary to most composts. 



Sulphate of Lime, (plaster of Paris,) usually 

 known as gypsum, supplies to the soil not only 

 lime, but also sulphuric acid, and previous to 

 undergoing any change, it has the power of ab- 

 sorbing and giving off to water large amounts 

 of the gaseous products of the atmosphere, as 

 well as those consequent upon organic decay in 

 the soil ; it is found also to be valuable in de- 

 odorizing the effluvia of stables, compost heaps, 

 etc. In soils containing very minute proportions 

 of progressed inorganic materials, plaster is often 

 used to assist in the growth of clover. This in 

 turn throws down its deep roots, gathering 

 from the subsoil large amounts of inorganic 

 matter, elevating thm to the surface soil, and 

 on decaying, when ploughed under, enriching the 

 soil, not, as has been frequently asserted, by the 

 decomposition of matters abstracted from the 



atmosphere alone, but by its power in progress- 

 ing the inorganic materials of the soil, and ren- 

 dering them fit for future assimilations. 



Wood-ashes. These supply to the soil large 

 amounts of potash, with smaller quantities of 

 the other constituents shown in their analysis. 

 Thus leached ashes from which the potash is 

 entirely removed, still exercise, on many soils, 

 a friendly influence, by furnishing plants with 

 the other constituents making up their com- 

 position, all of which, once having been in or- 

 ganic life, are progressed and fitted for entering 

 a higher class of vegetable growth. 



Lime, ashes, and other alkaline substances, 

 tend to alter the mechanical conditions of soils ; 

 clayey soils are rendered more free by their 

 use, while sandy soils become more compact, 

 each being improved in degree. 



Our space will not permit any further detail 

 on the subject of fertilizers; however, it should 

 be remembered that all those which are not of 

 a volatile character may be applied to the more 

 immediate surface with greater benefit than 

 when ploughed deeply under ; for, in the former 

 case, as they become soluble by the combined 

 effects of sun and air, and the consequent chem- 

 ical changes, they are presented to a greater 

 number of particles attacking their surfaces, and 

 coming in contact with a larger quantity of roots, 

 than if they had been originally placed more 

 deeply in the soil. Thus we find that the top- 

 dressing of grass and grain crops with phosphates, 

 ashes, etc., is of material benefit, while lime, from 

 the peculiar shape of its particles, descends from 

 the effects of rains and dews ; and in soils which 

 have not been subsoiled, the accumulation of 

 lime applied during many years, will be found 

 coating the surface of the subsoil, and can be 

 brought into activity again only by an in- 

 creased depth of ploughing of the surface, or the 

 disturbance of the subsoil. Lime, therefore, 

 should always be applied in small doses, and 

 more frequently than has been usually prac- 

 tised. The chief benefit to be derived from the 

 ploughing in of green crops, the application 

 of meadow muck, river mud, and other cheap 

 organic substances, is as follows : they fur- 

 nish large amounts of progressed inorganic ma- 

 terials ; during their decay or subdivision, they 

 leave interstices in the soil for the reception 

 of atmosphere ; the process of decay generates 

 heat, and this accelerates growth; and they 

 supply large amounts of carbon, evenly divided, 

 which perform the offices in the soil to which, 

 we have before referred. 



It should be remembered that a soil, surface- 

 ploughed to a reasonable depth, then subsoil- 

 ploughed and fully underdrained, containing fer- 

 tilizers of the kinds suggested above, has ad- 

 vantages over soils differently prepared ; among 

 which are the entire absence of any ill effect 

 from drought, greater ease of manipulation, 

 and the presence of conditions by which all that 

 class of plants, known as tillering plants, can, 

 increase the number of their bearing shoots. 

 A single grain of wheat will sometimes, by til- 



