the supposed new Metal Dofimm. 257 



digestion renewed ; but as no diminution in the quantity of 

 precipitate appeared to take place, the digestion was not con- 

 tinued, but the liquor was filtered. These solutions being 

 mixed evaporated to dryness, and the residue heated to redness 

 in a platinum crucible, there remained a fused mass of a light- 

 brown colour : its fusion was doubtless owing to the chloi'ides 

 of potassium and sodium, derived from the flux previously 

 used : this mass when treated with hydrochloric acid gave a 

 solution which afforded a slight greenish-coloured precipitate 

 with hydrosulphate of ammonia, and there remained on the 

 filter a small portion of an insoluble gelatinous substance, 

 exactly resembling alumina. 



My endeavours to obtain an ammoniacal solution of the 

 substance contained in Davidsonite having been thus frus- 

 trated, I redissolved the precipitate left by ammonia in di- 

 lute hydrochloric acid, and submitted this solution, and the 

 solution of alumina and iron, before described, to the action 

 of the following tests ; the results of which, for the sake of 

 comparison, I have arranged in the following manner. 



A. refers to the solution of donium as described by Mr. 

 Richardson, B. to the solution of the substance I obtained 

 from Davidsonite, and C. to the solution of alumina and oxide 

 of iron. 



Ammonia gave with A. " a white flocky precipitate soluble 

 in excess"; with B. a gelatinous precipitate slightly soluble in 

 excess of the precipitant ; and with C. a gelatinous precipitate 

 partially soluble in an excess of the precipitant. 



Carbonate of ammonia with A. the same as with ammonia; 

 with B. a white flocculent precipitate; when excess of carbo- 

 nate of ammonia was added and the solution filtered, hydro- 

 sulphuric acid gave a very slight green precipitate, therefore 

 it is slightly soluble in excess; with C. it acted in precisely 

 the same manner as B. 



Caustic soda with A. " white flocky precipitate soluble in 

 excess" ; B. and C. were also at first precipitated, and then 

 by an excess of the precipitant redissolved. 



Carbonate of soda gave with A. a " white flocky precipitate 

 insoluble in excess;" with B. a white flocculent precipitate 

 also insoluble in excess; with C. the same. 



Hydrosulphate of ammonia with A. produced a " flocky 

 green precipitate," with B. a beautiful dark-green flocculent 

 precipitate : C. acted in a like manner to B. 



Oxalate of ammonia with A. no precipitate, with B. and 

 with C. none. 



Phosphate of ammonia gave with A. a curdy white precipi- 

 tate: with B. a dense white precipitate; with C.the same as B. 



Third Series. Vol.9. No. 54. Oc/. 1836. 2G 



