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advantage in its use consists in its powerful action 

 upon silicates. Lime kunkur, as it is called in 

 India is the common denomination of a mineral 

 more correctly spoken of as carbonate of lime, 

 which is met with in all parts of the world in a 

 more or less pure state. 



The purest carbonate of lime contains in a 

 caustic state 56 per cent, of lime and 44 per cent, 

 of carbonic acid. Such a pure mineral is, however, 

 seldom found in India. Carbonate of lime is 

 generally met with in the state of nodules, called 

 kurikur, which contain a large proportion of foreign 

 matter, chiefly silica, alumina, phosphates, iron, and 

 magnesia. If these nodules of impure carbonate of 

 lime are exposed to a great heat, the carbonic acid 

 will separate from the lime and be driven off into 

 the air, leaving the lime in what is called its caustic 

 state, commonly known as quicklime. 



Quicklime, when sprinkled over with water, or 

 otherwise exposed to the influence of moisture, begins 

 to swell, breaks up spontaneously into small pieces, 

 and falls finally into an impalpable powder, called 

 " slaked lime." If, in this state, it is added to 

 clay, diffused through water, the mixture thickens 

 almost instantaneously, and, if suffered to remain 

 for some time, muriatic acid will dissolve the clay, 

 previously unacted upon by that medium, into a 

 gelatinous mass. The caustic lime had combined 

 with the elements of the clay, and liberated the 



