100 OF FERTILIZERS. 



334. Quicklime is limestone, chalk, or shells, deprived 

 of their carbonic acid by heat in a fire or a lime-kiln. 

 Quicklime amends a soil by decomposing some of its 

 ingredients, and by setting at liberty the potash and other 

 alkalies which exist in combination with clay and in par 

 ticles of granitic sand. It also hastens the decay of 

 organic substances, and combines with some of the gas 

 eous products given out during the process. It should be 

 in a state of powder, before it is scattered upon the soil. 

 It combines with the carbonic acid which is always in the 

 air and constantly brought down by rain, and thus 

 returns to the state of carbonate of lime. 



This, by itself, is insoluble in water, but water contain 

 ing carbonic acid has the power of dissolving carbonate 

 of lime, and thus the carbonate so formed and that 

 already in the limestone rocks are dissolved, and the 

 rocks are disintegrated. 



It also acts upon plants by diminishing the evaporation 

 from their surface, and thus husbands the moisture in the 

 soil, and makes it last longer than it would without the 

 lime. This same effect is also produced by gypsum, 

 nitre, common salt, and most of the other saline manures. 



335. An excellent way of using lime is in a compost, 

 as is practiced in Flanders. Make a layer of lime, and 

 cover it with a layer of sods, weeds, scrapings of ditches 

 and roads, river mud, marsh mud, and any thing else rich 

 in organic substances. Follow with successive layers of 

 lime and of the organic matter, and cover with a coat of 

 loam. At the end of a fortnight, it may be worked over, 

 and this may be repeated, from time to time. The longer 

 it remains in a heap, the more complete is the mixture, 

 in id the better the compost. 



