Refusing to accept this dictum, Pasteur demonstrated that crystals thought to be similar were different, and explained the seeming inconsistency. .

             "He found that a beam of polarized light was rotated to either the right or the left as it passed through a pure solution of naturally produced organic nutrients, whereas when polarized light was passed through a solution of artificially synthesized organic nutrients, no rotation took place. If, however, bacteria or other microorganisms were placed in the latter solution, after a while it would also rotate light to the right or the left" (Grant 48). His work laid the foundations for later study of the geometry of chemical bonds. Pasteur"s investigations soon brought him recognition and also a spot as assistant to a professor of chemistry. .

             As a result of his discovery in 1848 he devoted himself to what he called dissymmetry, "pointing out that inorganic substances are not dissymmetrical in their crystallization, while all of the products of vegetable and animal life are dissymmetric" (Grant 50). He concluded that there was some great biological principal underlining this. .

             Soon after his discovery he was made professor of physics at the Lycee of Dijon; three months later he became deputy professor of chemistry at the University of Strasburg, and full professor in 1852; in 1854 dean and professor of chemistry at the University of Lille; in 1856 the English Royal Society conferred on him the Rumford Medal for researches on the polarization of light with hemihedrism of crystals; in 1857 he became doctor of scientific studies at the Paris Ecole Normal, in 1863 professor geology and chemistry at the Ecole des Beaux arts, in 1867 professor of chemistry at the Sorbonne, where he remained till 1889, when he became the director of the Pasteur Institute, founded in his honor. (Vallery-Radot 39).

             While at the University of Strasburg he met Marie Laurent, daughter of the rector of the university.