Hematoxylin- We always manage to take a little home with us whether it's on our hands, scrubs or shoes. Our work spaces need special attention after using it because it's stain power is so great. So where does our dirtiest, yet important, step in work come from?The stain Hematoxylin is a natural dye derived from the Haematoxylum campechianum or logwood tree. This tree is found throughout Guatemala, Belize, and the Yucatan Peninsula of Mexico. The bark and sapwood of the tree are extremely hard and protect the very hard, very heavy, deep red-colored heartwood of the tree. Haematoylum derives its name from the Greek word "haemato" for blood and "xylo" for wood. Interestingly enough, hematoxylin is extracted from chips of the heartwood using hot water or steam and has been used to treat diarrhea and dysentery and the seeds are used locally as a flavoring for food. It is then oxidized to form a compound with strongly colored metal ions in it.
The Spanish discovered Hematoxylin in 1502 and began trading it with Europeans who used it for dying fabrics. English political economist Sir William Petty estimated that the average value of merchandise a ship of the 1600's could carry in a year was 1000-1500 pounds of sterling. A single load of 50 tons of logwood was worth more than an entire year's cargo of other merchandise! Because of the wood's great value the British logwood ships were a constant target for pirates. There were also frequent conflicts with the Spanish over the right of the British to settle in Belize and cut logwood. During the eighteenth century Spanish troops attacked the logwood camps many times. During the 1700's and 1800's, France encouraged its chemists to explore the dyeing properties of this logwood. In 1810, a French chemist named Michel Eugene Chevreul isolated hematoxylin crystals. The combination of hematoxylin with eosin was first proposed in 1871, forming one of the most used combinations in histology today. The compound is used to stain the nuclei of all the cells prior to examination under a microscope. Interestingly, in the 1970's due to the over cutting of forests in Brazil and Central America, there was a shortage of logwood and therefore of hematoxylin.
Be sure to use your stain wisely!
The deeply fluted, corrugated trunk of logwood is unmistakable
in the dense jungle of northern Belize
A freshly-cut piece of heartwood from a logwood tree along the New River turns the water in this container a blood red. The hematoxylin dye dissolves readily in fresh water
The scenic New River of the northern Belize, where Baymen (logwood cutters) once harvested logwood. The trees still grow in the dense tropical forest and jungle along the river
Leaves and branches of the logwood tree
To this day, a black and white logwood cutter are depicted in the national emblem of Belize, which appears on the currency and the Belize flag.