M. Boussingault's Analysis of a New Mineral. 143 



The solution, after the separation of the lead, was agitated 

 with a small excess of the nitrate of silver. This precipitated 

 6.6 grains of chloride of silver, corresponding to 1.3 grains of 

 hydrochloric acid. Ammonia was then added, after the excess 

 of silver was precipitated by a few drops of hydrochloric acid, 

 and the hydrochlorate removed by filtration ; this produced a 

 gelatinous deposit, which weighed 7.1 grains after a red heat. 

 This deposit might contain oxide of lead. It was therefore 

 treated with boiling hydrochloric acid. There was formed hy- 

 drochlorate of lead, which was separated, and alcohol then add- 

 ed to the acid solution. The hydrochlorate of lead weighed 4.0 

 grains, which corresponds to 3.2 grains of oxide ; so that the 

 total quantity of oxide of lead in the mineral amounted to 73.8 

 grains. The acid alcohohc solution was evaporated, and satu- 

 rated with caustic potash, in order to dissolve the alumina. The 

 alcaline solution, when saturated with nitric acid, and precipi- 

 tated by ammonia, gave 2.2 grains of alumina. 



The ammoniacal solution, which could only contain the mo- 

 lybdenum and chromic acid, was evaporated to dryness, during 

 which it assumed a dark yellow colour. The salts of ammonia, 

 principally its nitrate, were thus expelled, and there remained a 

 pulverulent greenish-white residuum, which was a mixture of 

 molybdic acid and oxide of chrome. 



There adhered to the sides of the platinum capsule, in which 

 the ammoniacal salts were volatilized, a fusible, extremely acid 

 substance, which possessed all the characters of phosphoric acid. 

 This acid was taken up by alcohol, the solution diluted with 

 water, and the alcohol expelled by boiling. It was then satu- 

 rated with ammonia, and precipitated by nitrate of barytes, 

 which yielded 4.0 grains of phosphate of barytes, which of course 

 contained 1.3 grains of phosphoric acid. The mixture of mo- 

 lybdic acid and oxide of chrome, which weighed 10.9 grains, 

 was treated with caustic potassa; there remained undissolved 

 0.9 grains of oxide of chrome, corresponding to 1.2 of chromic 

 acid. 



From this analysis, the mineral of Pamplona contains : 



