ACTION OF SALTS. 115 



pot into pearl ashes, for the purposes of glass manu- 

 factures, &ic. This residuum has been used with the 

 most signal success, when mixed in the proportion 

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

 of soil alone. — (See Colman's fourth Report, page 

 344.) The silicate of potash, depending entirely for 

 its conversion into carbonate of potash, is properly- 

 considered in the class of carbonates. 



166. The second class of salts, belonging to the 

 1st division, or nourishers are the nitrates, including 

 not only saltpetre, both East Indian and South Amer- 

 ican, or nitrate of potash and nitrate of soda, but also 

 all composts of lime, alkali, and animal matter. 

 These produce ammonia, which, without the lime 

 would act on geine, and render that soluble. Am- 

 monia, by the mere act of presence, hastens decay ; 

 but without the influence of lime, ammonia is changed 

 to a nitrate of that base, or to nitrate of ammonia. 



167. Thus in a compost of animal matter with- 

 out alkaline bases, not only has not all the geine been 

 rendered as soluble, as is usually supposed, by the 

 action of ammonia, but the absence of alkali has caus- 

 ed the ammonia, before its full action has occurred 

 on the organic matter, to be converted into a nitrate 

 of that base. But if the lime exceeds that which the 

 nitric acid can saturate, then the soluble geine is sei- 



