18 August 1868 August 17, 2019 Author: Staff French astronomer Pierre Janssen discovers helium. [rdp-wiki-embed url=’https://en.wikipedia.org/wiki/Helium’] Famous Words of Inspiration..."The force of public opinion cannot be resisted when permitted freely to be expressed. The agitation it produces must be submitted to." Thomas Jefferson — Click here for more from Thomas Jefferson Related posts: 18 August 1868 18 August 1868 18 August 1868 17 March 1958 28 July 1868 25 July 1868 7 December 1995 21 October 2015 28 September 1868 12 January 1967 Categories: History Tags: 18 August, 1868