It was known by the 19th century that a compound called salicin relieved pain effectively. However, salicylic acid was tough on stomachs and a means of buffering it was needed. In 1853, the chemist Charles F. Gerhardt neutralized salicylic acid with sodium and acetyl chloride, thereby creating acetylsalicylic acid. Gerhardt, however, had no desire to market the product and abandoned the discovery. In 1899, Felix Hoffmann, who worked for a German company called Bayer, rediscovered Gerhardt's formula. Hoffmann tried it on his father, who was suffering from arthritis. When he proposed marketing the drug, the head of Bayer's pharmacological institute sent a reply letter that included:

"This is typical Berlin hot air. The product is worthless"

Ultimately, Bayer's chairman interceded and the company marketed the drug. Aspirin was patented on Feb. 27th, 1900.