^gO ANALYSIS ON SODALITE. 



du.lat^ed with nitric acid, and poured upon the filter. The 

 powder retained upon the filter was washed, dried, and heat- 

 ed to redness. It weij^hed 37*2 grains, and was silica, 



4. The liquor which had passed through the filter was 

 Supersaturated with carbonate of potash, and the copious 

 white precipitate which fell collected by the filter, and 

 boiled while yet moist in potash-lie. The bulk diminished 

 greatly, and the undissolved portion assumed a black co- 

 lour, owing to apme oxide of mercury with which it was con- 

 taminated. 



5. The potash-lie being passed through the filter, to free 

 it from the undissolved matter, was mixed with a sufficient 

 quantity of sal-ammoniac. A copious white precipitate fell, 

 which being collected, washed, dried, and heated to redness, 

 weighed 27*7 grains. This powder, being digested in sulphu- 

 ric acid, dissolved, exceptO*22 of a grain of silica. Sulphate 

 of potash being added, and the solution set aside, it yielded 



Alumine. alum crystals to the very last drop. Hence the 27'48 grains 

 of dissolved powder were alumina. 



6. The black residue, which the potash-lie had not taken 

 TLip, was dissolved in diluted sulphuric acid. The solution 

 being evaporated to dryness, and the residue digested in hot 



Lime. water, a white soft powder remained, which, heated to red- 



ness, weighed 3*6 grains, and was salphate of lime, equiva- 

 , lent to about ^grains of lime. 



7. The liquid from which the sulphate of lime was sepa- 

 rated, being exactly neutralised by ammonia, succinate of 



Oxide of iron, ammonia was dropped in ; a brownish red precipitate fell, 

 wiiich, being heated to redness in a covered crucible, weigh- 

 ed one grain, and viras black oxide of iron. 



-8. The residual, liquor being now examined by different 

 reagents, nothing farther could be precipitated from it. 



9. The liquid (No. 4.) from which the alumina, lime, and 

 irori had been leparated by carbonate of potash, being 

 boiled forborne time, let fall a small quantity of yellow- 

 coloured niatter. This matter being digested in diluted 

 sulphuric acid, partly dissolved, with effervescence; but a 

 •portion rerfiained~undissolved, weighing 1 grain. It was in- 

 solubk in* acids, and with-potash melted into a colourless 

 Sttex. glass. It was therefore filica. The sulphuric acid solution 



.V V . '' being 



