In 1849, Louis Pasteur resolved a problem concerning the nature of tartaric acid [REF].
In 1874, Jacobus Henricus van 't Hoff[REF] and Joseph Achille Le Bel[REF] independently proposed that this phenomenon of optical activity in carbon compounds could be explained by assuming that the 4 saturated chemical bonds between carbon atoms and their neighbors are directed towards the corners of a regular tetrahedron.