No. 6. 



0)1 the Preparation and Use of Manures. 



173 



it renders the earth more capable of absorb- 

 ing tlie moisture of the atmosphere. When 

 salt is applied as a manure, it may be used 

 in quantities from six to fifteen bushels per 

 acre ; although some have gone as higii as 

 fifty bushels. Farmers, however, should be 

 cautious how thoy venture on excessive 

 doses, as an extravagant one could scarcely 

 fail of being fatal to any crop. Legrand, in 

 his experiments with salt, found that it grad- 

 ually improved the crop of barley, until six- 

 teen bushels per acre was reached, when it 

 gradually dimuiished, until the amount of 

 forty bushels per acre was reached, when 

 vegetation Was destroyed. Salt combined 

 with manure, has proved very efficient; and 

 in the Woburn experiments, the wheat so 

 treated, exceeded all others. The most fa- 

 vourable proportions were found to be 45 

 tons of dung, and five and a half bushels of 

 salt per acre ; the manure ploughed in, the 

 salt sown with the seed. The experiments 

 that have been made, would seem to indi- 

 cate that a preferable mode of using salt, in 

 most cases, would be to sow it on tlie land 

 some weeks before the seed is to be put in. 

 In this case, where lime exists in the soil, a 

 chemical change takes place, at least par- 

 tially, and muriate of lime and soda is the 

 result. Such a change would seem to be 

 most favourable to vegetation. 



t^all and Lime. — Salt and lime, artificially 

 mixed as a manure, promise to be a valu- 

 able aid to the farmer in those position? 

 where the soil abounds with insoluble sili- 

 cates or geine, and wliere other manures 

 necessary to produce decomposition or fer- 

 mentation, are not at hand. Prof Johnston 

 recommends a mixture of two parts of lime 

 and one part of salt, the mixture to remain 

 incorporated in a shady place, or covered 

 with sods two or three months before using. 

 Salt and lime should not be used immedi- 

 ately after mixing, as bad results are apt 

 to ensue; but after being well mixed in a 

 dry state, and lying as directed, it may 

 be applied at the rate of thirty to sixty 

 bushels per acre, either before or at the 

 time of sowing. Mixed with soot, salt acts 

 with great power on roots. Mr. Sinclair 

 mixed six and a half bushels of soot with 

 the same quantity of salt, and used the mix- 

 ture on lands sowed to carrots. Tlie result 

 was, that unmanured land gave twenty-three 

 tons of roots per acre, and the manured yield- 

 ed forty tons per acre ; and Mr. Cartwright 

 found that where unmanured soil gave 157 

 bushels of potatoes per acre, 30 bushels of 

 soot and six of salt, made it produce 240 

 bushels per acre. Dr. Dana furnishes so 

 beautiful an explanation of the manner in 

 which this manure acts, that it deserves a 



place entire : " By mixing quicklime with 

 common salt, its soda is let loose, the acid 

 combines with the lime, forming a soluble 

 salt of lime, and so long as the soda remains 

 caustic, it has no effect on the muriate of 

 lime, but as soon as the soda becomes mild 

 or carbonated, decomposition of the muriate 

 of lime is produced, and the common salt 

 regenerated. Commencing then with quick- 

 lime and salt, we pass to a soluble salt of 

 lime and caustic soda, and from that to mild 

 soda, and to carbonate of lime and the origi- 

 nal salt. If these various changes take 

 place in the midst of peat or geine, it is 

 evident that the caustic soda acts upon the 

 geine, and also evolves ammonia from that 

 substance; secondly, that the muriate of 

 lime, in its finely soluble state, insinuates 

 itself among the particles of the geine; that 

 the soda is also equally diffused, and that 

 when the soda becomes carbonated, it pro- 

 duces an almost impalpable carbonate of 

 lime throughout the whole mass, which, by 

 its equal diffusion tlirough the soil with the 

 geine, acts upon the silicates, as has been 

 heretofore explained." To produce these 

 effects. Dr. D. directs to take one bushel of 

 salt and two bushels of lime ; to make the 

 salt into strong brine, and with it slack the 

 lime. Mix both well together, and let them 

 remain ten days; then let them be well 

 mixed with three cords of peat, shovelled 

 well over for about six weeks, when it may 

 be used. A quantity of salt sufficient to de- 

 stroy all vegetation, may be applied to a soil 

 with safety, when a few months are to elapse 

 before the crop is to be put on ; as the che- 

 mical changes which take place, partially 

 neutralize its effect during this time. A 

 small quantity mixed with the soil in each 

 hill of corn, has been found to protect it 

 from the wire-worm and the cut-worm ; in^ 

 deed, there is no substance that insects of 

 all kinds more dread than salt. It is proba- 

 ble, therefore, that further experiments wi)! 

 show that not the least value of salt is to be 

 found in its preventive properties against 

 these depredators. 



Charcoal. — Charcoal is a valuable manure, 

 and applied directly to the soil in a pulver- 

 ized state, produces excellent effects. It 

 acts by rendering the soil more permeable 

 to atmospheric air, by absorbing and retain- 

 ing for the use of plants, the ammonia of the 

 atmosphere, or such as falls in showers ; by 

 rendering soils with which it is incorporated 

 warmer; and by furnishing a constant sup- 

 ply of carbonic gas to growing plants. The 

 great productiveness of what are called coal 

 hearths, or those places on which charcoal 

 has been burned, has long been a common 

 remark, but this has been commonly attri-. 



