Salicylic acid the product with sulfuric acid gives salicylic acid: It can also be prepared by the hydrolysis of aspirin (acetylsalicylic acid) or methyl salicylate (oil of wintergreen) with a strong acid or base. Hippocrates, Galen, Pliny the Elder and others knew that willow bark could ease pain and reduce fevers. It was used in Europe and China to treat these conditions. This remedy is mentioned in texts from ancient Egypt, Sumer and Assyria. The Cherokee and other Native Americans used an infusion of the bark for fever and other medicinal purposes. In 2014, archaeologists identified traces of salicylic acid on 7th
Gallic acid cyclic ether-esters (depsidones). Gallic acid is commonly used in the pharmaceutical industry as a standard for determining the phenol content of various analytes by the Folin-Ciocalteau assay; results are reported in gallic acid equivalents. Gallic acid can also be used as a starting material in the synthesis of the psychedelic alkaloid mescaline. The name is derived from oak galls, which were historically used to prepare tannic acid. Despite the name, gallic acid does not contain gallium. Salts and esters of gallic acid are termed "gallates". Gallic acid is an important component of iron gall ink, the standard European writing and