DESCRIPTION AND ANALYSIS OF A MINERAL, ETC. Ill 
to twenty grains. The sulphuric acid thus separated amounts 
to 6.86 grains. 
It hence follows that the salt is a sulphate, and it remained 
to ascertain the base. 
Chloride of platinum had no effect upon a concentrated so- 
lution of the salt, and consequently the base is not potassa. 
When a strong solution of potassa was added to the solu- 
tion, no ammoniacal odor was emitted. 
When a small portion of the salt is held in the outer flame 
of the blow-pipe, it communicates a deep yellow hue to the 
flame, which is characteristic of soda ; hence the salt must be 
sulphate of soda. 
If a sulphate of soda, 6.86 grains of sulphuric acid, require 
5.38 grains of soda for saturation, then 6.86 + 5.38=12.24 grs. 
of sulphate of soda, while the amount of salt employed was 12.5. 
Sixty grains o f the impure anhydrous salt was dissolved in wa- 
ter and filtered, to separate the impurities. By treating the 
solution with oxalate of ammonia, about one per cent, of oxa- 
late of lime was obtained, equal to about .044 of lime. 
The mother waters remaining after crystallizing the sul- 
phate of soda, were suffered to evaporate to one-fifth, and the 
remainig fluid allowed to drain off. The crystalline matter 
which resulted consisted of sulphate of soda, interspersed with 
small cubic crystals. A number of the cubes were separated. 
When the cubic salt was added to a drop of concentrated 
sulphuric acid, and a glass rod moistened with ammonia held 
over it, copious white vapors resulted. 
Another portion was dissolved in water, nitrate of baryta 
added to separate any adhering sulphate, and the liquor filtered. 
When nitrate of silver was added to the solution, a white pre- 
cipitate resulted which was soluble in ammonia. The crystals 
also decrepitate by heat, and tinge flame yellow, and are hence 
chloride of sodium. 
The liquid drained off in the last experiment was mixed 
with alcohol, and nitrate of baryta added to get rid of the sul- 
phuric acid — of the sulphate, then filtered and evaporated to 
dryness — the dry mass digested in alcohol, and the solution 
