242 Vineyard Culture. 



to fourteen and one-half per cent, of that material, and there- 

 fore must be valuable applications to the vineyard. Immense 

 quantities of these marls are dug, and shipped to considerable 

 distances, by water and by rail. The deposit is extensive in 

 West Jersey. 



In many places calcareous marls are found, that can not fail 

 to prove useful, if applied as a top-dressing, or used in the 

 preparation of composts. 



Quicklime is a most valuable material to apply as a modi- 

 fier of the soil, and it exerts the happiest effects. This ma- 

 terial enters largely into the improved agriculture of many 

 portions of our country ; even on limestone soils, the appli- 

 cation is found to be of great value, but upon those which arc 

 deficient in calcareous matter, it is of especial utility. The 

 lime is carted into the field, and distributed in piles, where it 

 is allowed to slake by exposure to the moisture of the atmos- 

 phere, which reduces it to a fine powder ; it is then called 

 air-slaked lime (chemically, a hydrate). This powder is 

 spread evenly upon the surface, generally of grass land, and 

 plowed in with a winter fallow. From fifty to two hundred 

 bushels may be applied to the acre. 



One" of the most valuable applications of quicklime, is 

 made by putting it into the compost heap, with any rough 

 materials, such as chips, shavings, or brush, mingled with sods 

 and the soil. These substances are rapidly reduced, under 

 the influence of the lime, to a fine pulverulent mass, that makes 

 excellent manure. Lime should never be added to nitrogen- 

 ous matters, as it causes the elimination and escape of the val- 

 uable ammonia, that is thus lost. 



To fix and retain this important nitrogenous material, an- 

 other salt of lime is used the sulphate, or plaster of Paris, 

 gypsum the action of which is to change the volatile car- 

 bonate of ammonia into the sulphate, while the lime becomes 

 a carbonate ; neither is volatile, and the ammonia is then said 



