History of aspirin mid-eighteenth century. By the nineteenth century pharmacists were experimenting with and prescribing a variety of chemicals related to salicylic acid, the active component of willow extract. In 1853, chemist Charles Frédéric Gerhardt treated acetyl chloride with sodium salicylate to produce acetylsalicylic acid for the first time; in the second half of the nineteenth century, other academic chemists established the compound's chemical structure and devised more efficient methods of synthesis. In 1897, scientists at the drug and dye firm Bayer began investigating acetylsalicylic acid as a less-irritating replacement for standard common salicylate medicines, and identified a new way to synthesize it.
Bark hack The first sentence is basically correct except that the blade is straight rather than curved. With the bark hack, only the bark is removed; it does not cut into the wood as the wood hack did. The wood hack was used up until the early 1950's and the trees were "chipped or streaked" each week during the sap flow season. With the bark hack, only the bark was removed and a 50% sulfuric acid solution was sprayed on the "streak" and it had to be done only every 2 weeks. Bark hack A bark hack is a tool used to