Willow bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and in Ancient Greece the physician Hippocrates wrote about its medicinal properties in the fifth century BC. Native Americans across the Americas relied on it as a staple of their medical treatments. It provides temporary pain relief. Salicin is metabolized into salicylic acid in the human body, and is a precursor of aspirin. In 1763, its medicinal properties were observed by the Reverend Edward Stone in England. He notified the Royal Society, which published his findings. The
Fluoroacetic acid Fluoroacetic acid Fluoroacetic acid is a chemical compound with formula CHFCOOH. The sodium salt, sodium fluoroacetate, is used as a pesticide. It inhibits the aconitase step of the citric acid cycle. Fluoroacetate occurs naturally in at least 40 plants in Australia, Brazil, and Africa. It is one of only five known organic fluorine-containing natural products. It was first identified in "Dichapetalum cymosum", commonly known as gifblaar (Afrikaans) or poison leaf, by Marais in 1944. As early as 1904, colonists in Sierra Leone used extracts of "Chailletia toxicaria", which also contains fluoroacetic acid or its salts, to poison rats. Several native