He then wrote about a bitter powder that came from the bark of the willow tree that could ease pains and reduce fevers. It was also mentioned in texts from other areas like Lebanon and Assyria. The Native Americans used an infusion of the bark for fever and other purposes.
The medicinal part of the plant is the inner bark of the tree. The active extract of the bark is called salicin after the Latin name for the white willow tree. It was isolated in crystalline form in 1828 by Henri Leroux, a French pharmacist. Raffaele Piria, an Italian chemist was able to convert it to salicylic acid. Salicylic acid was isolated from the herb called meadowsweet by German researchers in 1839. While it was somewhat effective, it also caused digestive problems when consumed in high doses.
A French chemist, Charles Frederic Gerhardt, first prepared acetylsalicylic acid in 1899 and was the first to name it aspirin. This preparation of aspirin was one of many reactions Gerhardt conducted for his paper on anhydrides and he did nothing further with it. Six years later in 1859, von Gilm created the substance again.
In 1897, a chemist at Friedrich Bayer and Co. obtained acetylsalicylic acid and claimed to discover aspirin. Regardless of that, aspirin was finally manufactured and put on the market to help those in pain or with fever.