Felix Hoffmann in 1890 with the pharmaceutical state exam. In 1891 he graduated magna cum laude from the University of Munich. Two years later he earned his doctorate, also magna cum laude, after completing his thesis entitled "On certain derivatives of dihydroanthracene". In 1894, he joined Bayer as a research chemist. On 10 August 1897 Hoffmann synthesized acetylsalicylic acid (ASA) while working at Bayer under Arthur Eichengrün. By combining salicylic acid with acetic acid, he succeeded in creating ASA in a chemically pure and stable form. The pharmacologist responsible for verifying these results was skeptical at first, yet once several large-scale studies
Willow flute tempered scale. Modern willow flutes are typically made of plastic (PVC tubing is often used), but the original willow flutes were made from sections of bark cut from green willow branches. Willow flutes could only be made this way during the spring, and became unplayable when the bark dried out. Noted modern willow flute artists include the group Hedningarna and Anders Norudde of Sweden. Other Scandinavian groups that use the Seljefløyte in traditional arrangements include Eivind Groven, Steinar Ofsdal, Groupa and Bask. There is also a Karelian variant of the willow flute that is made in Finnish Karelia and the