The pods of several South American species of Caesalpinia, including C.
brevifolia (algarobilla), C.
coriaria (divi-divi) and C. spinosa (tara) yield an important source of
natural tannins. The tannins react
with collagen protein in animal skin, converting the skin into leather. The
heartwood from a thorny South
American tree called brazilwood (C. echinata) contains a red dye used for
cotton, wool and inks. During
the Middle Ages the main commercial source of this dye came from an Indian
species (C. sappan), called
"bresil" or "brasil" by Portuguese traders, is referring to the bright red
heartwood. Early in the sixteenth
century, Portuguese discovered the South American species and transferred
the Old World name to
it--eventually becoming known as brazilwood. In fact, brazilwood is the
national tree and namesake of the
country Brazil. Brazilwood is also highly prized for violin bows and is
occasionally cultivated as an
ornamental tree in southern California.

In the early 1900's the red dye of brazilwood, called brazilin, was highly
acclaimed as a nuclear stain in
histological preparations and as an indicator in acid-base titrations. The
dye becomes yellowish in acid
solutions and carmine-red in alkaline solutions. Brasilin is similar in its
properties and uses to hematoxylin,
another dye from a Central American tree called logwood (Haematoxylon
campechianum). Because of
the striking red heartwood, logwood is also called "brasil" or "palo de
tinta" in Mexico. The exportation of
logwood was an important factor in the early settlement of British Honduras,
known today as Belize.

Brazilwood extract powder (#3616) and brazilwood, pernambuco, cut pieces
(#3615) - sold in 100g or 1kg.
Available from Kremer Pigments, Inc. NY, NY.
1-212-219-2394.

Eric Kellar
Histology/Immunohistochemistry
University of Pittsburgh Medical Center

	----------
	From:  Neal E. Beeman [SMTP:beemanne@york.uchsc.edu]
	Sent:  Sunday, January 03, 1999 12:53 PM
	To:  histonet@Pathology.swmed.edu
	Subject:  brazilin

	Does anyone know where I could purchase a stain called brazilin also
called
	natural red 24?