388 Chemical Society. 



and gave a solution of a darker green than the first. This solution 

 was left several weeks in open vessels, and upon its being drawn off, 

 a quantity of the green precipitate was found adhering to the bottom 

 and sides of the vessels. 



The composition, which is very variable, of the mineral Pitchblende, 

 as given by Berthier in his Traitd des Essais par la voie seche from 

 two analyses, is in the 100 parts, — 



Protoxide of uranium 51'6 60*0 



Carbonate of magnesia 3*3 



Peroxide of iron 7*2 2*5 



Alumina (clay) 17*2 9-0 



Sulphuret of iron and copper 1*2 5*5 



Arsenical pyrites (iron) 5-8 9*2 



Sulphuret of lead 6*0 3*5 



Sulphuret of zinc , . . . 1*4 



Carbonate of lime 2*2 2'2 



Water and bitumen 4*2 5*2 



98-7 98-5 

 No mention is here made of the phosphoric acid which enters into 

 the composition of the artificial uranite. The composition of the na- 

 tive uranite, as also of the double phosphate of uranium and copper 

 (chalkolite), are thus given by Berzelius : — 



Uranite. Chalkolite. 



Oxide of uranium 59'37 60-25 



Lime i 5 - 65 



Oxide of copper 8'44 



Barytes 1*51 



Magnesia and oxide of manganese '19 



Phosphoric acid 14'63 15*56 



Water 14'90 15*05 



Gangue 285 '70 



Fluoric acid and oxide of tin ... . trace 



9910 lOO* 

 It appears that these two minerals are found mixed together in all 

 proportions, and from the artificial compound which forms the sub- 

 ject of the present notice, containing both oxide of copper and lime, 

 that it is also a mixture of these salts. 



The following analysis of the " Artificial Uranite," made under 

 the superintendence of Mr. Parnell, was read as an appendix to the 

 above j — 



Phosphate of uranium 49* 



Oxide of copper 19*5 



Lime 1*8 



Water 21*5 



Phosphoric acid in combination with"! „ „ 



oxide of copper and lime (loss) . . . . / 



100-00 

 The process of analysis was the following : — 

 (1.) Having previously ascertained by a qualitative analysis that 



