340 Chemical Examination of Microlite. 



Analysis. 



A. 0"33 gramme of the mineral in the state of an impalpable 

 powder was treated in, a platina crucible with 1-50 bi-sulphate of 

 potassa. After fusion for a few minutes over an alcoholic lamp, the 

 crucible was carried to redness in the furnace. The color of the 

 fused mass was yellowish white. 



B. Water was boiled on the fused mass (A,) and the contents of 

 the crucible transferred at once to a filter. The clear solution that 

 passed through was treated with solution of sulphate of potassa. In 

 fifteen minutes, afine white granular precipitate appeared. 



C. The insoluble powder, B, was treated with sulphohydrate of 

 ammonia. Its color was thereby changed to greenish black with a 

 tinge of blue. Hydrochloric acid was poured on until the powder 

 became nearly white. After washing in boiling water, it was trans- 

 ferred to a platina crucible and after ignition weighed 0"37 gramme. 



D. The ignited powder, C, was boiled for a few minutes with 

 excess of carbonate of potassa, and then treated with hydrochloric 

 acid, filtered, washed, dried^and ignited. It weighed 0-255 gramme. 

 A portion of it was fused with carbonate of soda before the blowpipe. 

 The bead effervesced, and on cooling, became white and opake. 

 Another portion was fused with borax. It gave a clear bead, and 

 by flaming became white and opake. 



E. The hydrochloric solution, D, was precipitated with oxalate 

 of ammonia and the precipitate was heated to whiteness. It weigh- 

 ed 0'04 gramme. 



■F. The water boiled on the fused mass of the mineral and treated 

 with solution of sulphate of potassa, B, was separated from its crys- 

 talline precipitate by means of a filter and set aside after having had 

 its volume augmented by a saturated solution of sulphate of potassa. 

 In a few days a precipitate of fine granular white crystals appeared. 

 The fluid was treated with an additional quantity of sulphate of po- 

 tassa, whereby the white precipitate was in part, perceptibly dissolv- 

 ed. The clear liquid was withdrawn and treated with ammonia. A 

 light yellowish white flocculent precipitate appeared, which on igni- 

 tion was greyish white, without a tinge of red. The quantity was 

 too small to allow me to make any satisfactory experiments upon 

 it ; but the fact that the double salt it formed was not soluble in the 

 solution of sulphate of potassa, shows that it could not be thorina or 

 zirconia, while its not turning red on ignition proves that it was not 

 oxide of cerium. 



