History of aspirin tree in 1758 and noticed an astringency reminiscent of the standard—and expensive—ague cure of Peruvian bark. He collected, dried, and powdered a substantial amount of willow bark, and over the next five years tested it on a number of people sick with fever and agues. In his letter, Stone reported consistent success, describing willow extract's effects as identical to Peruvian bark, though a little less potent. (In fact, the active ingredient of Peruvian bark was quinine, which attacked the infectious cause of malaria, while the active ingredient of willow extract, salicin, relieved the symptoms of malaria but could not cure
History of aspirin "Bayer Aspirin" made up only a small fraction of the British aspirin market because of competition from "Aspro", "Disprin" (a soluble aspirin drug) and other brands. Bayer Ltd began searching for new pain relievers to compete more effectively. After several moderately successful compound drugs that mainly utilized aspirin ("Anadin" and "Excedrin"), Bayer Ltd's manager Laurie Spalton ordered an investigation of a substance that scientists at Yale had, in 1946, found to be the metabolically active derivative of acetanilide: acetaminophen. After clinical trials, Bayer Ltd brought acetaminophen to market as "Panadol" in 1956. However, Sterling Products did not market "Panadol" in