154? Intelligence and Miscellaneous Articles. 



filter and redissolved in hydrochloric acid. In this solution oxide of 

 iron and alumina were precipitated by carbonate of ammonia, the 

 oxide of uranium remaining in solution, and care being taken that 

 the solution should be quite dilute, in order that the iron might be 

 entirely precipitated. The oxides of iron and alumina were sepa- 

 rated by caustic potash. In the solution filtered from these sub- 

 stances, the uranium was precipitated by adding hydrochloric acid 

 to supersaturation, boiling to expel all the carbonic acid, and then 

 adding ammonia. 



In the solution from which the precipitate by ammonia of uranium, 

 iron and alumina had been separated, the lime was thrown down by 

 ammonia and oxalic acid. The filtered solution was evaporated to 

 dryness, and the ammoniacal salts driven off by ignition, when there 

 remained traces of magnesia and manganese. 



The water was estimated by ignition in a bulb-tube, and collecting 

 the water driven off in a weighed chloride of calcium tube. The 

 mineral does not however part with any of its carbonic acid at a 

 temperature below that required to drive off all the water, nor is it 

 rendered less soluble by exposure to the strongest heat of a Berzelius 

 lamp. 



No traces of sulphur could be found by boiling the mineral with 

 fuming nitric acid, and testing wdth chloride of barium. The lead 

 has therefore been calculated as oxide, and not as a sulphuret. 



The per-centage results of two analyses are as follows :-— 



I. II. 



Silica 4-35 5'60 



Alumina 090 



Oxide of iron • 2'24 r 



Oxide of uranium 59'30 57*54 



Oxide of lead 5'36 5'84 



Lime 14-44 13-47 



Carbonic acid 7'47 



Water 4*64 



Magnesia and manganese traces 



98-70 

 That the uranium exists in the mineral as U 2 O 3 , and not as 

 VO U 2 O 3 , as in the common pitchblende, is evident from its ready 

 solubility in acids ; and that the oxide of uranium, or uranic acid as 

 it might with equal propriety be called, is in chemical combination 

 in the mineral is equally evident, from the fact that its solubility is 

 not diminished by ignition. That the silica is also chemically com- 

 bined is shown by the fact that it is separated in a state in which it 

 is soluble in carbonate of soda. It is difficult to see in exactly what 

 manner these elements are combined with regard to each other, 

 though it is probable that the oxide of uranium plays the part of an 

 acid toward a portion of the lime (the remaining portion being in 

 combination with the carbonic acid) and the lead. The frequent 

 occurrence of a small quantity of oxide of lead with the ores of 

 uranium is an interesting fact, on which future investigations may 

 perhaps throw some light. — Boston Journal of Natural History, 

 vol. vi. p. 37. 



