1825.} M. Berzelius on Uranium. 279 



Atoms. 



Barvtes 1 'SI containing oxygen 0-160 . . I 



Lime ^-QQ 1'585 .. 1 



Magnesia 1 n.^g 0-07 



Oxidule of mangau. J 



Oxide of uranium. .. 59*37 3* 128 .. 2 



Phosphoric acid .... 14"63 8* 193 . . 5 



Water 14'90 13-246 . . 8 



Gangue. 2-70 



Fluoric acid 1 rp -^j^g 



Ammonia / 



99-06 



It follows from this that the oxygen of the oxide of uranium is 

 double that of the lime ; that the sum of the oxygen of all the 

 bases is to that of the phosphoric acid as 3 : 5 ; and that the 

 oxygen of the water is eight times that of the lime. The quan- 

 tity of water actually found rather exceeds this proportion, but 

 the slight excess is probably in combination with the salts of 

 lime and barytes, and with the fluoric acid and ammonia. This 

 salt is, therefore, composed of 3 atoms of subphosphate of lime 

 (in the same degree of saturation as in crystallized apatite), 

 4 atoms of subphosphate of oxide of uranium, and 48 atoms of 

 water, mechanically intermixed with very minute quantities of 

 the phosphates of barytes, magnesia, and oxidule of manganese. 



Concentrated sulphuric acid developes the fluoric acid more 

 decisively than ignition, but the quantity is in both cases so 

 inconsiderable, that it cannot be regarded otherwise than an 

 accidental admixture, as indeed appears to be the case with it in 

 all the native phosphates. 



(B.) U rani te from Cornwall. — The small stock whicli I pos- 

 sessed of this mineral permitted me to subject it only to a single 

 analysis ; but my results agree so closely with those of Gregor 

 and Phillips, that a repetition of it would perhaps be super- 

 fluous. 



One gramme, previously pounded and dried in a temperature 

 of 68", lost by ignition in a small glass retort 0-1505 ; the 

 expelled water was neither acid nor ammoniacal, and was in all 

 respects pure. The yellow coloured residue was fused with 

 carbonate of soda, and the acid and alkali were extracted with 

 water. The oxides thus separated had a dark green colour, and 

 left by solution in muriatic acid and supersaturation with car- 

 bonate of ammonia, an insoluble matter, weighing 0-007 grm. 

 which contained silica, alumina, and a distinct trace of tin or 

 lead. The liquid was concentrated until the whole of the 

 ammonia was expelled, the precipitated oxides were then dis- 

 solved in muriatic acid, and the copper was thrown down by 



