Untersuchungen über die wasserfreien organischen Säuren.

In 1853 French chemist Gerhardt was the first to prepare acetylsalicylic acid (marketed by Bayer as asprin in 1899). Gerhardt called the compound he obtained "salicylic-acetic anhydride" (wasserfreie Salicylsäure-Essigsäure). However, Gerhard did not pursue the matter further. Digital facsimile from Google Books at this link.