XX 



crumbs of that bread wliidi, in 1846, was cast so liberally upon the 

 waters. I rejoice, ladies and gentlemen, in the opportunity here 

 afforded me of offering my tribute to the greatest worker of the :iu r( s 

 and of laying some of the blossoms of that prolific tree which he 

 planted at the feet of the great discoverer of diamagnetism." 



This phenomenal success with such a critical audience at once 

 established Tyndall's reputation as a clear and powerful expositor of 

 experimental science ; and, in the following July, he was unanimously 

 elected Professor of Natural Philosophy in the Royal Institution. It 

 was in the physical laboratory of this Institution that the whole of 

 Tyndall's subsequent work was performed, in so far as it was not 

 work involving the personal observation of natural phenomena in 

 the Swiss Alps and elsewhere ; for, although he occupied the chair 

 of physics in the Government School of Mines for several years, no 

 laboratory was provided for him or his pupils in that Institution. 



The following is Tyndall's own account of his first lecture given in 

 his ''Faraday as a Discoverer" : " In December, 1851, after I had 

 quitted Germany, Dr. Bence Jones went to the Prussian capital to 

 see the celebrated experiments of Du Bois Reymond ; and influenced, 

 I suppose, by what he heard, he afterwards invited me to give a 

 Friday evening discourse at the Royal Institution. I consented, not 

 without fear and trembling, for the Royal Institution was to me a- 

 kind of dragon's den, where tact and strength would be necessary to 

 save me from destruction. On February llth, 1853, the discourse 

 was given, and it ended happily. I allude to these things, that I may 

 mention that, though my aim and object in that lecture was to sub- 

 vert the notions both of Faraday and Pliicker, and to establish, in 

 opposition to their views, what I regarded as tho truth, it was very 

 far from producing in Faraday either enmity or anger. At the con- 

 clusion of the lecture he quitted his accustomed seat, crossed the 

 theatre to the corner into which I had shrunk, shook me by the hand, 

 and brought me back to the table." 



To return to Tyndall's first physical paper, published as a joint 

 investigation by Knoblauch and himself : by employing a method, 

 proposed by Dove, they examined the optical properties of crystals 

 and found that these optical qualities went hand in hand with their 

 magnetic observations. For a long time, these experiments led to 

 the discovery of no fact of importance ; but at length, the observers 

 met with various crystals whose deportment could not be brought 

 under the laws of magne-crystallic action as announced by Pliicker. 

 They also discovered cases which led them to imagine that this 

 magne-crystallic action was by no means independent, as alleged, 

 of the magnetism or diamagnetism of the mass of the crystal. In 

 short, the more they worked at the subject the more clearly was it 

 revealed to them, that the deportment of crystals in the magnetic 



