243 



I came to Paris for my literary studies ; he has done so by hundreds. 

 How many youug men in science and art has he not been the first to 

 encourage ! How many great institutions and researches has he not 

 first conceived and helped to organize without any reference to his per- 

 sonal comfort or honour ! And there is to me, above all, that one most 

 striking fact for the honour of our race ; it is this, that his heart as well 

 as his mind has never ceased to become larger. It is a general observa- 

 tion, that arrived at a certain age, men shut themselves up against the 

 outer world, their interest decreases, their sympathies grow fainter. 

 Not so with Humboldt : his soul has always expanded, his interests 

 and sympathies for every great national and human interest have 

 always been warmer, his care for the welfare of the rising generation 

 always more affectionate, his hopes for the future of the world 

 always brighter. I know no one more youthful aiid hopeful mind 

 than Humboldt's, and I therefore may well say in every respect, that 

 in honouring him you have not only honoured my country and science 

 in general, but Humanity. 



It is for these reasons, my Lord, that I beg earnestly to thank you. 



The President then proceeded as follows : — 



Mr. Stokes, 



It is with sincere pleasure I discharge the duty which has 

 devolved upon me of placing in your hands the Rumford Medal. 

 Your discoveries in Physical Optics during the last few years, which 

 have shown in so striking a manner the powers of analysis in bringing 

 the abstruse phenomena of light within the domain of theory, have 

 been crowned by a discovery even more important. That the re- 

 frangibility of light should be actually changed by dispersion within 

 certain media, and that the invisible rays of the spectrum should thus 

 be rendered visible, is a discovery as curious, perhaps as important, 

 as any to be found in the recent history of optical science. 



I am sure I but express the feeling of this meeting, when I say 

 I confidently hope that a career commenced so brilliantly, may in its 

 course be distinguished by other discoveries of equal value, and that 

 you may contribute still further to extend the fame of that celebrated 

 university where you received your education, and for which you are 

 now making so signal a return. 



Mr. Joule, 



In the slight sketch I have already given of the progress 

 of different departments of science under the aid of the Govern- 

 ment Grant, I have noticed your labours in conjunction with the 

 other eminent men engaged in the wide field of Molecular Physics. 



The subject to which you have especially devoted your energies, 

 the discovery of the mechanical equivalent of heat, is one which 

 unites in itself a practical, as well as a deep scientific interest. To have 

 carried out with great ingenuity and perseverance a series of beauti- 

 ful and conclusive experiments, is an important achievement, and I 

 am most happy it has found its reward in the Medal Vvdiich I have 

 the pleasure of presenting to you. 



