URANIUM. 21 



place ; and after the sulphate of barytes had 

 precipitated, the clear liquid was tested with glau- 

 ber salt and with muriate of barytes, but did not 

 become in the least muddy by the addition of 

 either, showing that it contained no sensible 

 quantity of barytes or sulphuric acid ; but 

 33-125 = 13-25 x 2-5. Consequently, 51 grains 

 of the salt contain 12*5 grains of sulphuric acid, 

 which is equivalent to 2 atoms of that acid. 



(3.) 51 grains of crystallized salt were dis- 

 solved in water, and mixed with an excess of 

 ammonia, which precipitated the peroxide of 

 uranium in yellow flocks. The whole was 

 thrown upon a filter, and the peroxide was 

 washed repeatedly with caustic ammonia, till it 

 was judged to be freed completely from all ad- 

 mixture of sulphate of potash. This method 

 was employed, because it was found, that when 

 pure water was used to wash the peroxide of 

 uranium, a portion of it was redissolved. The 

 liquid which passed through the filter was eva- 

 porated to dryness in a platinum vessel, and then 

 the whole was heated to redness to expel all the 

 ammoniacal salt : the residual salt was white, with 

 a scarcely perceptible shade of yellow ; it weighed 

 11*2 grains. Being redissolved in water and 

 mixed with ammonia, a few yellow flocks were 

 precipitated, which being collected on a filter 

 and dried, weighed, as nearly as could be deter- 

 mined, exactly 0-2 grain : the salt possessed the 



B3 



