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SALTS OF POTASH NITER. 101 



Uses, It is a valuable article in medicine, and is em- 

 ployed by tinmen in soldering; also, mixed will) iron filings 

 or turnings to pack the joints in steam apparatus. 



Mascagnine — Sulphate of Ammonia. In mealy crusts, of a yellow- 

 ish-gray or lemon-yellow color. Translucent. Taste pungent and 

 bitter. Composition, sulphuric acid 533, ammonia 228, water 239. 

 Easily soluble in water. Occurs at Etna, Vesuvius, and the Lipari Is- 

 lands. It is one of the products from the combustion of anthracite coal 



Phosphate of ammonia, bicarbonate of ammonia, and phosphate of 

 magnesia and ammonia have been found native in guano. The last ifl 

 identical with struvite. 



Struvite. A phosphate of ammonia and magnesia, containing 13 

 per cent, of water. It occurs in yellowish subtransparent rhombic crys- 

 tals. G=l-7. H=l. Slightly soluble in water. Found on the site 

 of an old church in Hamburg, where there had been quantities of cattle 

 dung. 



2. POTASSA. 

 niter. — Nitrate of Potash. 4\fc 



Trimetric. In modified right rhombic prisms. M : M 

 il8° 50'. Usually in thin white subtransparent crusts, 

 and in needleform crystals on old walls and in caverns. 

 Taste saline and cooling. 



Composition : potassa 46*56, nitric acid 53'44. Burns 

 vividly on a live coal. 



Dif. Distinguished readily by its taste and its vivid 

 action on a live coal ; and from nitrate of soda, which it most 

 resembles, by its not becoming liquid on exposure to the air. 



Uses. Niter, called also saltpeter, is employed in making 

 gunpowder, forming 75 to 78 per cent, in shooting powder, 

 and 65 in mining powder. The other materials are sulphur 

 (12 to 15 per cent.) and charcoal, (9 to 12 £ for shooting 

 powder, and 20 for mining.) It is also extensively used in 

 the manufacture of nitric and sulphuric acids ; also for pyro- 

 technic purposes, fulminating powders, and sparingly in 

 medicine. 



Obs. Occurs in many of the caverns of Kentucky and 

 other Western States, scattered through the earth that form" 

 the floor of the cave. In procuring it, the earth is lixiviatea. 

 and the lye, when evaporated, yields the saltpeter. India is 

 its most abundant locality, where it is obtained largely for 



What does niter consist of ? What effect is produced when it io 

 put on a live coal ? What are its uses 1 Where does it occur ? 

 9* 



