cinnamic

By the addition of diluted sulphuric acid, the aldehyde of cinnamic acid is afterwards procured pure.

With fatty acids and acid anhydrides it gives the “Perkin” reaction (see Cinnamic Acid).

An isomer of cinnamic acid known as allo-cinnamic acid is also known.

It is perfectly soluble in alcohol and in ether, and gives out its acid (benzoic or cinnamic) to water.

The genuine balsam contains about 61⁄2% of benzoic (cinnamic) acid:—11.