Arthur Eichengrün the invention of aspirin in 1897. Impure acetylsalicylic acid (ASA, the active compound of aspirin) had been synthesized already in 1853 by French chemist Charles Frédéric Gerhardt; the 1897 process developed at Bayer was the first to produce pure ASA that could be used for medical purposes. Due to the rise of the Nazis in Germany, Eichengrün was unable to object when Hoffman first made the claim that "he" (Hoffman) invented aspirin, in the footnote of a 1934 German Encyclopedia. Hoffman's claim was once widely accepted, but many historians now consider it to be discredited. Eichengrün first claimed to have
Hippocrates of Chios geometry textbook for many centuries. Hippocrates is believed to have originated the use of letters to refer to the geometric points and figures in a proposition, e.g., "triangle ABC" for a triangle with vertices at points A, B, and C. Two other contributions by Hippocrates in the field of mathematics are noteworthy. He found a way to tackle the problem of 'duplication of the cube', that is, the problem of how to construct a cube root. Like the quadrature of the circle this was another of the so-called three great mathematical problems of antiquity. Hippocrates also invented the technique of