1637 - René Descartes quantitatively derives the angles at which primary and secondary rainbows are seen with respect to the angle of the Sun's elevation,
1833 - Heinrich Lenz[?] states that an induced current in a closed conducting loop will appear in such a direction that it opposes the change that produced it (Lenz's law),
1845 - Michael Faraday discovers that light propagation in a material can be influenced by external magnetic fields,
... and others, formed the "centre," midway between Erdmann and Gabler on the one hand, and the "extreme left" represented by Strauss, Feuerbach and Bruno Bauer.
Of his ...