STIMULATING MANURES. 71 



It is acknowledged that lime is principally useful upon 

 fallow lands which are broken up ; upon grass lands, 

 whether natural or artificial, which are prepared for culti- 

 vation ; and upon muddy lands, which are to be put into 

 a state fit for culture. It is well known, that in all these 

 cases there exists in the land a greater or less quantity of 

 roots, which, by the application of lime, may be made to 

 serve more immediately for manure, by the solubility it 

 will give to the new products formed by them ; but this 

 effect can be produced neither by spreading the lime on 

 the land at the time of sowing the seed, nor by throwing 

 it upon the soil without covering it, nor by sprinkling it 

 upon the plants which have begun to unfold ; it is neces- 

 sary to scatter it upon the land before the first tilling, and 

 only as fast as it can be mixed with the soil, as lime loses 

 its strength by exposure to the air. Subsequent tillages 

 mix it more intimately with the soil, and place it in con- 

 tact with the roots and stalks upon which it is to act, and 

 at the end of some months this action is completed. 



Independently of this effect, which, in my opinion, is 

 the most important, lime exercises other powers, which 

 make it a very valuable agent in agriculture. It cannot 

 be denied, that the long existence and the barrenness of 

 a marshy or turfy soil, give rise in such lands to myriads 

 of insects, which repeated tillages, and frequent changes 

 of crops, can destroy only in a great length of time; whilst 

 the mixture of lime with the earth performs the work im- 

 mediately. It is certain, that some plants which injure 

 the soil and the crops, escape every tilling ; but are imme- 

 diately destroyed by the action of lime. It is clear, that 

 to produce these effects, the lime must be applied in the 

 caustic state ; the mode of preparing it is as follows. 



As lime absorbs water with avidity, exhaling vapor and 

 producing noise and heat, and crumbling into pieces, that 

 liquid may be thrown upon it, till the whole mass is re- 

 duced to a dry and impalpable powder ; and it is in this 

 state that it must be used. 



In order to preserve the husbandman from the delete- 

 rious effects upon the lungs, of this light powder, it is best 

 to mix it with some moistened earth ; and in order that it 

 may preserve all its virtue, it is necessary that it should be 

 immediately buried in the soil by ploughing. 



The custom of employing air-slacked lime, which is 

 lime in the state of a sub-carbonate, is spreading in France 



