The alkaloid and most of its salts are crystalline.

B1. Concentrated nitric acid dissolves brucine to a deep red liquid, which on standing or heating becomes yellow.  After this has occurred dilute the solution and with this a reducing agent, like stannous chloride, will give a violet. An excess of nitric acid must be avoided or the reaction loses its sensitiveness.  The violet solution when made alkaline with sodium hydroxide changes to blue or green.  These changes are peculiar to brucine.

B2. Concentrated sulfuric acid dissolves brucine without producing a color.

B3. Chlorine water forms a bright red solution, the color being destroyed by an excess of the reagent and turned brownish-yellow by ammonium hydroxide.