Another eloquent example of the strange destiny of human thought in connexion with electricity is to be found in the work of Clark Maxwell, who, starting from Faraday's discoveries, gave the theory of electricity its mathematical basis. Along his purely theoretical line of thought he was led to the recognition of the existence of a form of electrical activity hitherto undreamt of - electro-magnetic vibrations. Stimulated by Maxwell's mathematical conclusions, Hertz and Marconi were soon afterwards able to demonstrate those phenomena which have led on the one hand to the electro-magnetic theory of light, and on the other to the practical achievements of wireless communication.