258 ANALYSIS. 



Defeription and in while clots, mixed with fome of a yellowtfli hue. Am- 

 minera^l from "lon'a. added in excefs, betrayed no fign of ihe prefence of 

 Cornwall, copper. 



(2.) The ammonia, on evaporation, was found to have held 

 a portion of the mineral in folution. A frefli portion of am- 

 monia diflblved more, but in a lefs quantity, at each fucceed- 

 ing affufion of it. 



(3.) The precipitate, which had refilled the ammonia, was 

 boiled in a lilver crucible, with a folution of potafti in alcohol, 

 diluted with diftilled water, and a confiderable portion of the 

 fubftance was diflblved by it : the potalh and the ammonia 

 had dilfolved rather more than half of the fixed ingredients 

 of it. 



(4'.) The edulcorated refiduum, which was of a dirty yellow 

 colour, was transferred to a crucible of platina, and moiftened 

 with fulphuricacid, which was abftra6ted from it, in ihefand, 

 bath. The brownith-gray mats was elixated with diflilled 

 water, which diflblved nearly the whole of it. The refiduum 

 confided of a white heavy powder, which, tried in diflfereHt 

 ways, was found to hejhlphate of lead, 



(5.) The folution efl^'eded by fulphuric acid was greenifli. 

 On evaporation, a fait was produced, of uncommon brilliancy, 

 refembling fcales of mica, or filver leaf. Thefe diminithed in 

 quantity at every frefti folution and evaporation, and at laft 

 they could not be reproduced; but aconfufed cryftallized mafs 

 remained. How far the platina crucible may have contributed 

 to this phenomenon I cannot afcertain. 



(6.) The folution of the faline mafs was precipitated by 

 potafli, of a dark brown colour. The potafli held nothing in 

 folution, I rediflTolved the precipitate in nitric acid, and preci. 

 pitated the folution by ammonia, of a bright yellow colour, 

 peculiar to the oxide of uranium, with which it agreed in other 

 properties. 



(7.) What was diflblved by ammonia (2.) amounted to 

 nearly ^ part of the fixed ingredients. It was white, inclining 

 to afh-colour. It tinged phofphate of foda and ammonia of a 

 light green. It was foluble in (ulphuric acid, except a few ge- 

 latinous flakes. The folution was greenifli ; gradually eva- 

 porated, it (hot into a number of minute fitllaled cryflalliza- 

 tions, which were circular, and confified of rays diverging 

 from a centre. They were, in general, colouiiefs: a few of 



them 



