146 M. Godon’s mineralogical observations. 
grew softer, and the supernatant liquor appeared of a yellow colour, 
indicating that the mineral had been attacked. 
The part remaining solid of this mineral was separated from the 
liquid. Well washed and dried, it weighed 85 parts ; its loss was 
consequently 15. Its colour was not much altered. 
The solution presented a deep yellow colour. United to the wa- 
ter of lixiviation, and submitted to evaporation till dryness, it aban- 
doned a precipitate consisting of sulphat of lime, which, when dry, 
weighed 17,058 (effective lime 5,50). 
A new quantity of water being added to dilute the remaining salts, 
this solution, again submitted to evaporation, when concentrated, 
gave a light precipitate with a concentrated solution of muriat of 
platina, and some traces of alum. This proves the presence of 
potash. =e ro ee ak 
_ Ammonia in excess poured into this solution, occasioned a floc- 
cous precipitate of a yellowish brown colour, consisting of alumina 
and the oxyds of manganese and iron. Calcined ina crucible, it 
weighed 6,075. 
The liquid, separated from this last precipitate, was submitted to a 
desiccation, and the sulphat of ammonia, vapourised in a crucible of 
platina, a fixed saline substance remained, weighing nine grains. 
This substance, diluted in water, and abandoned to crystallization, — S 
presented a mixture of two salts well characterized sulphat of potash, — 
and sulphat of soda. - o 
The difficulty of an exact separation of these two salts in so small 
a bulk, and the uncertainty of the proportions of the component parts 
the sulphat of soda, which arises from the great proportion of water 
it absorbs and loses by exposure to air and calcination, do not permit 
° 
