CARBONIC ACID FAILS TO DISSOLVE THE ALKALOID.
After the evaporation is completed, ether is added to the watch-glass: the alkaloid may, or may not, be dissolved. The ether is then evaporated at the ordinary temperature of the air.
Ether fails to dissolve the alkaloid.
It probably consists of berberine.
In this case, it will possess a yellow color, and its hydrochlorate will give a reddish-brown precipitate upon addition of sulphide of ammonia.
Ether dissolves the alkaloid.—A small portion is treated with nitric acid. If an intense green coloration is produced, the remaining portion is dissolved in ether, and an ethereal solution of oxalic acid added. If the precipitate now formed does not dissolve upon the addition of a little water, there is reason to suppose the presence of aricine.
Provided the addition of nitric acid did not produce a coloration, the mixture of the alkaloid and this acid is treated with a small quantity of sulphuric acid: if the fluid now acquires a red color, the substance probably consists of narcotine.
Should both nitric and sulphuric acids fail to cause a reaction, the alkaloid is dissolved in ether, precipitated by an ethereal solution of oxalic acid, and the precipitate treated with a little water. If it dissolves, it probably consists of papaverine.
CARBONIC ACID DISSOLVES THE ALKALOID.
The substance is treated with ether, notice being taken if it dissolves, which is evaporated at the ordinary temperature of the air so as to prevent a loss of minute portions of the alkaloid.