Dragon's blood

Dragon's blood is a bright red resin that is obtained from different species of a number of distinct plant genera: Croton, Dracaena, Daemonorops, Calamus rotang and Pterocarpus. The red resin has been in continuous use since ancient times as varnish, medicine, incense, and dye.

Name and source

A great degree of confusion existed for the ancients in regard to the source and identity of dragon's blood. Some medieval encyclopedias claimed its source as the literal blood of elephants and dragons who had perished in mortal combat. The resin of Dracaena species, "true" dragon's blood, and the very poisonous mineral cinnabar (mercury sulfide) were often confused by the ancient Romans. In ancient China, little or no distinction was made among the types of dragon's blood from the different species. Both Dracaena and Daemonorops resins are still often marketed today as dragon's blood, with little or no distinction being made between the plant sources; however, the resin obtained from Daemonorops has become the most commonly sold type in modern times, often in the form of large balls of resin.

Jane Yolen

Jane Hyatt Yolen (born February 11, 1939) is an American writer of fantasy, science fiction, and children's books. She is the author or editor of more than 280 books, of which the best known is The Devil's Arithmetic, a Holocaust novella. Her other works include the Nebula Award-winning short story Sister Emily's Lightship, the novelette Lost Girls, Owl Moon, The Emperor and the Kite, the Commander Toad series and How Do Dinosaurs Say Goodnight. She gave the lecture for the 1989 Alice G. Smith Lecture, the inaugural year for the series. This lecture series is held at the University of South Florida School of Information "to honor the memory of its first director, Alice Gullen Smith, known for her work with youth and bibliotherapy." In 2012 she became the first woman to give the Andrew Lang lecture.

Early life

Jane Hyatt Yolen was born February 11, 1939 at Beth Israel Medical Center in Manhattan, the first child of Isabell Berlin Yolen, a psychiatric social worker who became a homemaker upon Yolen's birth, and Will Hyatt Yolen, a journalist who wrote columns at the time for New York newspapers. Isabell also did volunteer work, and wrote short stories in her spare time, but they did not sell. Because the Hyatts, the family of Yolen's grandmother, Mina Hyatt Yolen's, only had girls, a number of the children of Yolen's generation were given their last name as a middle name in order to perpetuate it, including Yolen's brother, Steven Hyatt Yolen, who was born three and a half years later.

Blood

Blood is a bodily fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. When it reaches the lungs, gas exchange occurs when carbon dioxide is diffused out of the blood into the pulmonary alveoli and oxygen is diffused into the blood. This oxygenated blood is pumped to the left hand side of the heart in the pulmonary vein and enters the left atrium. From here it passes through the mitral valve, through the ventricle and taken all around the body by the aorta. Blood contains antibodies, nutrients, oxygen and much more to help the body work.

In vertebrates, it is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains dissipated proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and blood cells themselves. Albumin is the main protein in plasma, and it functions to regulate the colloidal osmotic pressure of blood. The blood cells are mainly red blood cells (also called RBCs or erythrocytes), white blood cells (also called WBCs or leukocytes) and platelets. The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron-containing protein, which facilitates oxygen transport by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion.

Dragon

A dragon is a legendary creature, typically with serpentine or reptilian traits, that features in the myths of many cultures. There are two distinct cultural traditions of dragons: the European dragon, derived from European folk traditions and ultimately related to Greek and Middle Eastern mythologies, and the Chinese dragon, with counterparts in Japan (namely the Japanese dragon), Korea and other East Asian countries.

The two traditions may have evolved separately, but have influenced each other to a certain extent, particularly with the cross-cultural contact of recent centuries. The English word dragon derives from Greek δράκων (drákōn), "dragon, serpent of huge size, water-snake".

Name

The word dragon entered the English language in the early 13th century from Old French dragon, which in turn comes from Latin draconem (nominative draco) meaning "huge serpent, dragon", from the Greek word δράκων, drakon (genitive drakontos, δράκοντος) "serpent, giant seafish". The Greek and Latin term referred to any great serpent, not necessarily mythological, and this usage was also current in English up to the 18th century.

Croton lechleri

Croton lechleri is a species of flowering plant in the spurge family, Euphorbiaceae, that is native to northwestern South America. It is commonly known as Sangre de Grado (Peruvian Spanish) or Sangre de Drago (Ecuadorian Spanish), both of which translate to "dragon's blood". They refer to this tree's (and several related species') thick red latex.

The latex has medicinal properties, and is used by local peoples as a liquid bandage, applied to seal wounds, as it dries quickly to form a protective skin-like barrier. Its use by native people has led to scientific study and observation of its in vitro antioxidant activity as well as its mutagenicity.

The latex also contains a number of chemicals, including taspine. Oligomeric proanthocyanidins, another kind of chemical contained in the latex, have been investigated for the treatment of HIV-associated diarrhea under the name crofelemer. In January 2013, crofelemer, under the trade name Fulyzaq, was approved by the FDA for the treatment of HIV-associated diarrhea.