Aspirin to salicylic acid, the active component of willow extract. In 1853, chemist Charles Frédéric Gerhardt treated sodium salicylate with acetyl chloride 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. By 1899, Bayer had dubbed this drug Aspirin and was selling it around the world. The word
Birch bark manuscript In Indian sculpture, a Birch bark manuscript is easily identified by the droop. A palm leaf manuscript is stiff. On July 26, 1951, during excavations in Novgorod, a Soviet expedition led by Artemiy Artsikhovsky found the first Russian birch bark writing in a layer dated to c. 1400. Since then, more than 1,000 similar documents were discovered in Staraya Russa, Smolensk, Torzhok, Pskov, Tver, Moscow, Ryazan, and Vologda, although Novgorod remains by far the most prolific source of them. In Ukraine, birch bark documents were found in Zvenyhorod, Volynia. In Belarus, several documents were unearthed in Vitebsk and Mstislavl. The