124 



ACTION OF SALTS. 



Hence, from 4 to 8 pounds in every 100 are valuable to 

 the farmer ; but the ashes are not worth the carting to any 

 great distance. Indeed, it is seen that the composition of 

 anthracite ashes is very nearly that of soil deprived of its 

 geine. 



165. It may be here rem.arked in relation to silicate of pot- 

 ash, that this substance forms a greater part of the residuum 

 produced in the conversion of pot into pearl ashes, for the 

 purposes of glass manufactures, &c. This residuum has been 

 used with the most signal success, when mixed in the pro- 

 portion of a barrel of this material with ten horse-cart loads 

 of soil alone. (See Colman's Fourth Report on the Agricul- 

 ture of Massachusetts, p. 344.) The silicate of potash, act- 

 ing entirely by its conversion into carbonate of potash, is 

 properly considered in the class of carbonates. 



