1) Ether crystalline 
Apiol is a phthalide, also known as parsley apiol, apiole or parsley camphor. It is found in the essential oils of celery leaf and all parts of parsley. Heinrich Christoph Link, an apothecary in Leipzig, discovered the substance in 1715 as greenish crystals reduced by steam from oil of parsley. In 1855 Joret and Homolle discovered that apiol was a...
• (n.) An oily liquid derived from parsley.
A'pi·ol noun [ Latin api um parsley + -ol .] (Medicine) An oily liquid derived from parsley.