PROCEEDINGS OF THE FARMERS' CLUB. 445 



used by the plants is shown by analysis to be small. The difference 

 in quality in lime is very great, so much so that for plant food 

 a single bushel of one kind of lime may be worth more than 

 several bushels of other kinds. When the secondary uses of lime 

 are called for, the difference is not so great. Lime decomposes 

 organic matter in the soil, and also changes the mechanical tex- 

 ture of soils, and for this purpose the kind of lime is of little im- 

 portance. The plains of Athens, as I have before remarked, 

 contain forty per cent of carbonate of lime, and many chalk 

 farms of England are said to contain a still larger percentage. 

 In our own limestone districts, the amount of lime in the soil is 

 much greater than that required by vegetation. It is in the con- 

 dition of limestone, but if it be heated red hot, and thus con- 

 verted into caustic lime, a season's exposure will restore the car- 

 bonic acid, and it will again become carbonate of lime in another 

 condition ; it will be more active, because it will be more com- 

 pletely divided, chemically and mechanically. Yet in West- 

 chester county, if you add 2,000 bushels of its lime to the acre, 

 which would be about two per cent of the weight of the soil to 

 the depth of twelve inches, it would render it barren. 



Shell lime is superior in its effects, where lime is needed as 

 direct food for plants. Burned oyster shells give us a lime which 

 may be profitably applied, even in our limestone districts, at the 

 rate of ten, twenty, fifty, or even one hundred bushels to the acre. 

 We find, too, that that part of the oyster shell which we usually 

 call the valve, or the eye, contains a trace of phosphorus, which 

 gives it a greater value. In making the lime and salt mixture, 

 which is done by decomposing one bushel of salt by three bushels 

 of lime, the salt being placed in solution, and the mixture form- 

 ing the chloride of lime and carbonate of soda, w^e find that it is 

 more active and more valuable as a manure, if made of shell lime, 

 than if made of stone lime. 



When we add too much lime to the soil, its mechanical texture 

 becomes unfriendly to cultivation, as in some portions of Hunter- 

 don county, N. J., where they have added lime to the soil until 

 it cracks. The remedy for over-limed land is to topdress with 

 salt. The dews and rains carry down its saturated solution into 

 the earth, until it disappears. It changes the lime into the chlo- 

 ride of lime, and forms carbonate of soda, and the land is restored. 

 I have seen many cases of the restoration of over-limed land in 

 this way. Lime is the remedy for soils where salt has been used 



