logwood
An aqueous extract obtained from the heartwood of
the logwood tree, Haematoxylon campechisnum, of
Central America and the West Indies. Logwood
contains approximately 50% haematoxylin (C
16 H 14 O6 . 3H 2
O), a colorless crystalline material when pure,
but which turns blood red when exposed to air. It
is only slightly soluble in water, but dissolves
in aqueous solution of alkalis to give a range of
colors from violet to black. It was taken to
Europe soon after the discovery of America, and
was one of the most important of the natural
coloring matters until the 19th century, when it
was superseded by synthetic dyestuffs of greater
brilliance. Logwood dye was used in producing
black ink, marbling colors, including purple and
violet, and is still used in dyeing leather and
textiles black. (233 )
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