When the alcoholic extract is employed, about half its weight of potassa should be used.
All kinds of vegetables do not yield the same proportion of potassa.
Sulphur, 16 parts; dried chloride of calcium, 23 parts; chlorate of potassa, 61 parts.
With sulphate of potassa it forms a double salt (manganese alum).
In this state it constitutes the ordinary or carbonate of potassa of the Pharmacopias.
A mixture of gamboge, 10 gr., with carbonate of potassa, 20 gr.
We must give preference, however, to the method by means of chlorate of potassa and hydrochloric acid.
Take of acetate of lime or of potassa and sal ammoniac, equal parts; mix and distil at a gentle heat.
We use fluorspar mixed with bisulphate of potassa as a test for lithia and boracic acid in complicated compounds.
This solution diluted with water, and then saturated with potassa, has a blue colour, which is most visible by reflected light.