298 PREPARATIONS OF MANGANESE. 
then heat the solution to ebullition, and pour in the solution of 
carbonate of soda from time to time, boiling after each addition? 
until the carbonate of manganese which it precipitates is free 
from sesquioxide of iron. This is easily ascertained by 
filtering off a few drops of the boiling solution, and adding 
to it a solution of yellow prussiate of potassa. If all the 
iron is separated, a white precipitate is produced, but if some 
yet remains, it will have a tinge of blue more or less deep, 
and of course more carbonate of soda should be added till 
the iron is all separated. 
Filter the solution from the oxide of iron, and add to it 
an excess of carbonate of soda; a bulky white hydrated car- 
bonate of manganese precipitates, which should be washed 
with cold boiled water, and thrown on a cloth to drain. 
It is now ready for the preparation of any of the soluble 
salts of manganese by solution with their respective acids, as 
the sulphate, chloride, malate, tartrate, acetate, etc. 
Carbonate of manganese is a white or pale rose colored 
powder, insoluble in water, and when heated much above 
100 F. is changed by its base passing to a higher degree of 
oxidation. It consists of two equivalents of protoxide of 
manganese, two equivalents of carbonic acid, and one 
equivalent of water. For medical purposes it may be used 
in three forms, viz. : 
1st. Pure in powder obtained by drying the moist carbo- 
nate above described at a temperature below 100° F. in a 
drying room or by spontaneous evaporation. It may 
be given in pills, powders, or mixed with syrup or muci- 
lage. 
2nd. In powder united with sugar, prepared by mixing 
the moist washed and pressed carbonate, obtained by pre- 
cipitating ten ounces sulphate of manganese with an excess 
of carbonate of soda, with four ounces of sugar in powder, 
and evaporating the moisture from the mixture on a water 
bath at a temperature not exceeding 130° F. till it is dry. 
This which may be called the saccharine carbonate of man- 
