280 M. Berzelius on Uranium. [ApRit, 



sulphuretted hydrogen gas. The sulphuret of copper weighed 

 after roasting 0*094 grm. Dissolved in muriatic acid and 

 mixed with muriate of barytes, it gave 0'028 grm. sulphate of 

 barytes, = 0"0096 grm. sulphuric acid ; consequently the oxide 

 of copper amounted to 0-0844 grm. The liquid which had been 

 treated with sulphuretted hydrogen was boiled in order to expel 

 the excess of gas, and precipitated by ammonia. The precipi- 

 tate, washed with a solution of sal ammoniac and ignited, gave 

 0*592 grm. oxidule of uranium, = 0*5025 grm. oxide. 



The alkaline liquid, which contained the acid of the uranite, 

 was supersaturated with muriatic acid, and precipitated by sul- 

 phuretted hydrogen gas : some sulphuret of arsenic separated, 

 but too inconsiderable to be weighed. The portion of green 

 uranite on which my original blowpipe examination was made, 

 contained a considerably larger quantity of arsenic acid : as 

 this acid is isomorphous with phosphoric acid, its proportion iu 

 different specimens will probably be liable to great variations. 

 The uranite was therefore composed of 



Atom. 



Oxide of copper 8*44 containing oxygen 1*702 . . 1 



Oxide of uranium. .... 60*25 3*175 .. 2 



Phosp. ac. with ars.ac. 15'56'* 8*72 .. 5 



W^ter 15*05 13*24 . . 8 



Gangue 0*70 



100-00 



Here we find the same multiples as in the uranite from Autua, 

 with the difference that the lime is replaced by a quantity of 

 oxide of copper, containing the same amount of oxygen. The 

 quantity of phosphoric acid is rather too high, because there is 

 included under it both the arsenic acid and the necessary loss 

 of the analysis. This uranite contains also fluoric acid, perhaps 

 more abundantly than the specimens from Autun, but the lime 

 and barytes are wholly wanting. 



Both these uranites are therefore double subphosphates of 

 oxide of uranium, the one with oxide of copper, and the other 

 with lime. As lime and oxide of copper, according to Mitscher- 

 lich's admirable discovery are isomorphous, they must, when 

 combined with an equal number of atoms of oxide of uranium, 

 phosphoric acid, and water, assume the same crystalline form ; 

 and, therefore, the two minerals will be considered as identical, 

 by those who confine themselves to the crystalline form, in esta- 

 blishing a mineralogies!,! species, although this arrangement, 

 with reference to their composition, is erroneous. 



* Pet«nviined from ths loss. 



