23 i Professor Connell on the 



half an hour. The semifused mass was then treated with 

 dilute muriatic acid, when the whole was dissolved except 

 a little light and flocky silica^ shewing, the complete decompo- 

 sition of the mineral. The crucible was 'not at all attacked. 

 The silica wa^ th^n sfeparflted ' in the lisual manner, and 

 weighed after ignition l!ll grain'. 



Ammonia threw down a precipitate which, after ignition, 

 weighed 1.81 grain. This was digested in muriatic acid, 

 and in two hours was nearly all dissolved. Water being 

 added, some white flocky matter was collected, which, when 

 ignited, amounted to 0.06 of a grain, and examined by the 

 blowpipe acquired a blue tinge with nitrate of cobalt, and 

 was evidently a mixture of alumina and silica. The filtered solu- 

 tion was treated with excess of caustic potash, w^hen the whole 

 of the precipitate formed was redissolved except 0.03 of oxide 

 of iron. The potash solution boiled with sal ammoniac gave 

 an abundant precipitate, which was insoluble in carbonate of 

 amm.onia, and gave a blue colour with nitrate of cobalt, and 

 thus had all the properties of alumina. By subtracting the 

 oxide of iron, we thus have 1.78 of alumina ; the residue of 

 0.06 grain left undissolved by the muriatic acid being held as 

 alumina, although it contained a little silica. The liquid 

 which had been treated with ammonia, gave no precipitate 

 with oxalate of ammonia, or when boiled with carbonate of 

 soda. 



It is thus evident that the mineral could have contained 

 no appreciable quantity of zirconia. If present, we should 

 expect it to have been left undissolved by the muriatic acid 

 after ignition of the ammoniacal precipitate ; and the solubi- 

 lity in potash of what had been taken up by the acid, was a 

 farther proof that this earth was not present. To make still 

 surer that none of it was mixed with the alumina, a portion 

 of the matter which had been held dissolved by the potash, 

 was dissolved in muriatic acid, and poured into an excess of 

 bicarbonate of potash, but no part of the substance was taken 

 up by the bicarbonate. 



We have therefore in the 3.02 grains under analysis— 



