120 Dr Turner's Analysis ofOxahverite. 



mixture was then evaporated slowly to dryness, and the so- 

 luble parts removed by dilute muriatic acid assisted by heat. 

 The silica, collected and heated to redness, weighed 11.65 

 grains, equivalent to 50.76 per cent. 



The acid solution was treated by pure ammonia in order 

 to separate iron and alumina ; and to the filtered liquid an 

 excess of the oxalate of ammonia was added. The oxalate of 

 lime, collected and exposed to a white heat, yielded 5.14, or 

 22.39 per cent of pure lime. 



The precipitate, consisting of iron and alumina, was treated 

 in the usual manner by pure potash. The peroxide of iron, 

 thus procured, amounted to O.78 of a grain, or 3.39 per cent ; 

 and the alumina to 0.23 of a grain, or 1 per cent. 



The solution from which the oxalate of lime was obtained, 

 was evaporated to dryness, and exposed to a red heat. The 

 fused residue consisting of the chloride of potassium, weighed 

 1.52 grains, equivalent to 0.96 of a grain, or 4.18 per cent, of 

 potash. 



To ascertain the quantity of water contained in the oxah- 

 verite, 6.45 grains of the crystals were Heated to redness. 

 The loss was 1.12 grains, or 17.36 per cent. 



On comparing the result of this analysis with that of apo- 

 phyllite and tesselite, as given by Berzelius, it will be seen 

 that the composition of these minerals is very analogous. 



Tesselite. 



52.38 

 24.98 

 5.27 

 0.00 

 0.00 

 0.64 

 16.20 



99.08 99.13 99.47 



As the proportion of silica, lime, potash, and water, in oxab- 

 verite, is so nearly the same as that of the other minerals, it 

 admits of doubt whether the iron and alumina, combined per- 

 haps with a little water, are not to be regarded as accidental 



