210 SCIENTIFIC AGRICULTURE. 



doubt that all our present knowledge of lime as a manure, 

 can be expressed in a few known and plain principles: we do 

 not assume that all is known about lime that may be known at 

 some future time, but that the facts can be much more briefly 

 and perhaps more clearly set forth than is done by most wri- 

 ters on agriculture. 



Lime is perhaps the most important mineral used as a ma- 

 nure. When applied to a soil entirely destitute of lime, the 

 quantity will necessarily be larger than at subsequent periods. 



The quantity used must be determined, as in all other cases, 

 by circumstances. No general rule can be given for its use, 

 but each one must judge from the facts in the case and pro- 

 ceed accordingly. Johnston says, "if we suppose one per cent 

 to be necessary, then upwards of 300 bushels of slaked lime 

 must be mixed with a soil six inches in depth, -to impart to an 

 acre this proportion." On wet, peaty, marshy, or clay soils, 

 more lime will be necessary than on dry, sandy and loose soils : 

 on soils which contain much organic matters also, more may be 

 used than on those nearly destitute of them. It is consider- 

 ed better economy to apply lime in smaller quantities and at 

 shorter intervals, than to use it in large quantities at more dis- 

 tant period?. 



Caustic lime should be applied to marshy and clay soils im- 

 mediately after slaking: when allowed to slake in the open air 

 spontaneously, without the use of water, it is more mild, and 

 better adapted to grass lands and young crops; but W 7 hen ap- 

 plied to naked fallow and mixed with the soil, it may be used 

 in either state. Burned lime is well adapted to the compost 

 form of manures. As quick lime dissipates the ammonia of 

 fermenting manures in the soil, it ought not to be applied at 

 the same time, nor to come in immediate contact with them : 

 it is best applied usually in the fall, or as long as possible be- 

 fore the next crop is sown. 



These principles apply only to caustic lime : unburned lime, 



