1840.J SENATE— No. 36. 79 



becoming divided, the soil is rendered permeable to the roots 

 of the plants, and accessible to air and moisture. What influ- 

 ence the plant itself exerts upon the carbonate of lime, or upon 

 lime in any other form of combination, is not determined. 

 The amount of any earthy matter taken up by the plant is a 

 very small quantity ; and it is not supposed that the plant has 

 the power of changing its nature. The carbonate of lime is a 

 substance scarcely soluble in water, or under any common at- 

 mospheric influences ; but it can be taken into the roots or ves- 

 sels of the plant oifly in the most minute state of division. 



The whole subject, indeed, is as much open to investigation 

 as in the beginning. Beyond a certain quantity, the applica- 

 tion of lime is decidedly prejudicial to soils, and the farmers in 

 the best agricultural districts of Scotland, acknowledge that 

 their soils have been materially injured by the application of 

 lime to their farms. There, however, it has been applied in quan- 

 tities of hundreds of bushels to the acre, and much beyond any 

 amount in which it is ever likely to be applied here. 



Berkshire Marls. — The application of the Berkshire marls, 

 which contain more than ninety per cent, of carbonate of lime, 

 has not been attended with those beneficial efl'ects, which were 

 anticipated. The experiments have as yet by no means been 

 decisive. As yet these marls have availed little, but a hope 

 is expressed that they may hereafter prove beneficial. The 

 application has been made to gravelly loams, where the effects 

 could not have been expected to be so beneficial as upon clay 

 or peat soils. In the latter case, if applied, it may be expected 

 to assist much in producing a fine division of the soil. 



This mechanical division of the soil by the application of 

 finely powdered carbonate of lime, either after it has been com- 

 minuted by calcination, and the pure quick lime has passed 

 into the state of a carbonate, which it will soon do after being 

 exposed to the air, or in the condition of finely powdered lime- 

 stone, is that which is chiefly to be relied upon. The carbon- 

 ate of lime is scarcely soluble in water, though it is decompos- 

 ed by the access of several of the vegetable acids, and by the 



