408 
ELEMENTARY CHEMICAL MICROSCOPY 
C. Through Fusion with a Mixture of Sodium Carbonate and 
Potassium Nitrate. 
The fusion should be made in a small platinum cup or 
upon platinum foil, using the smallest possible amount of the 
fusing mixture which will react with the unknown. It is always 
wise to first obtain the hydroxide or oxide and employ this 
material for the fusion. 
If manganese is present a green color is obtained, due to the 
formation of manganates of sodium and potassium Na2Mn04, 
K2Mn04. 
Iron and chromium mask the reaction. 
EXPERIMENTS. 
a. Test several different Mn compounds by fusing on platinum foil or in a bead 
on Pt wire. 
D. By Means of Phosphates in Ammoniacal Solution. 
Manganous salts are precipitated as NH 4 MnP 04-6 H 2 O. 
See Magnesium, Method B, page 350; Nickel, Method B, 
page 412; Cobalt, Method C, page 414. 
Add to the slightly acidified test drop, ammonium chloride 
and secondary sodium phosphate, then add ammonium hydroxide 
by Method I. 
The hemimorphic crystals obtained usually grow somewhat 
longer than those of magnesium but are otherwise identical. 
They are proved to be due to manganese by adding hydrogen 
peroxide which causes them to turn brown. 
E. By Means of Sodium Bismuthate. 
Dissolve the material in concentrated nitric acid and 
evaporate the solution to dryness. Dissolve in dilute nitric acid, 
add several small portions of sodium bismuthate, stirring after 
each addition, allow to stand a short time; a pink or purple color 
results with a precipitation of brown oxide of manganese. Next 
add very carefully in tiny fragments sufficient, no more, sodium 
thiosulphate to dissolve the precipitate oxide. A colorless milky 
drop results; add a drop of nitric acid (1:4) and stir thoroughly. 
Now again add carefully and slowly a very little at a time sodium 
