2^0 AKALYSXS. 



Defcriptlon and Ammonia precipitated what remained in thefe folations, 

 minefa*l"/rom ^"^ redifTolvcd a part of the precipitates, which agreed in 

 CoruwalU properties with that fubftance before mentioned (2.) ; the 



remainder was of a brighter yellow. But I could not bring 



the fokition of it in nitric acid to cr) flallize. 



B. 



(1.) Some of the yellow cryftals, which had not the flighteft 

 appearance of beJDg contaminated with extraneous matter, were 

 difl'olwd in fulphuric acid. Silica was feparated ; and the pre- 

 fence of lime and lead proved by the appearance of their 

 xe^^e&ive, fulphatcs. 



(2.) If fulphate of ammonia is dropped into a folution of 

 this mineral in nitric or muriatic acids, no change takes 

 place, immediately. But on evaporation, a yellowilh cruft 

 is depofited, which is infoluble in water. A folution of car-, 

 bonate of foda in water, boiled on it, becomes yellowifli- 

 brown, and the greater part of it is diflblved. The re- 

 iiduum, which is white, is reduced on charcoal to a globule 

 of lead. What the carbonate of foda had diflblved was 

 found to be oxide of uranium. Sulphuric acid alone, does not 

 produce this depofited crufl. 



(3.) Some perfedly pure cryftals were diflblved in mu- 

 riatic acid. Some filica was feparated. A few drops of 

 fulphuric acid were dropped into the folution, which pro., 

 dticed no immediate change: on evaporation a white powder-, 

 feparated, which confified in part of fulpliate of lime. The 

 remainder, expofed to the flame of the blowpipe, was re- 

 duced to globules of lead. 



The folution was decompofed by ammonia, which redif- 

 folved a part of the precipitate; and, after edulcoration, the 

 precipitate was diflblved by nitric acid, and precipitated 

 again by ammonia, which held a lefs quantity in folution. 

 The edulcorated precipitate was now boiled with a folution 

 ©f carbonate of foda, which difTolved a large portion of it. 

 The folution was yellowifli-brown, and contained oxide of 

 uranium. What was undiflblved by the carbonate of foda 

 was diflblved in fulphuric acid, and feemed to be the fame 

 fubftance as that which the ammonia held in folution, 



A. (?.) 



Tho 



