242 J. L. Smith on determining the Alkalies in Minerals. 
capsule with a little water, (the funnel must be washed with a 
_ little water,) small quantities of a solution of carbonate of am- 
monia added, and the solution gently evaporated nearly to dry- 
ness. This is done to separate what little lime may have es- 
caped the first action of the carbonate of ammonia or. may have 
passed through the filter (22) in solution in carbonic acid. If 
any of the earths soluble in carbonate of ammonia existed in the 
mineral, those now become separated along with the lime. 
28. A little more water is now added to the contents of the 
of ammonia into the platinum capsule or crucible, and covering 
it up so as to have an ammoniacal atmosphere around the: : 
which will ensnre the volatilization of the last traces of free sal 
phuric acid. The alkalies are now in the state of pure sul phates 
may be weighed as such. The manner of separating the 
alkalies from each other will be mentioned in the second part o 
this paper. ie 
30. Thus far the mineral has been supposed to contain we 
magnesia. If this alkaline earth be present, we take the resid é 
as found in the capsule, (26) dissolve it in a little water, ne 
add sufficient pure lime-water,* to render the solution alka en 
boil and filter; the magnesia will in this simple way be § paral 
from the alkalies. The sclution which has passed through ded 
filter is treated with carbonate of ammonia in the manner all 
aise. | | ee ee - 
* If lime water be made it is well to an it of lime of the best quality, and 
ates two three portions of distilled water shaken up should be thrown 8¥0 
as containing the amount of alkali ti p : { 
