THE NEW TIIEOUY OF MATT hi:. 495 



REFLECTIONS SUGGESTED BY THE NEW THEORY OF 



MATTER. 



By the Right Honorable ARTHUR JAMES BALFOUR, 



PRESIDENT OF THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 



r PHE meetings of this great society have for the most part been held 

 *- in crowded centers of population, where our surroundings never 

 permit us to forget, were such forgetfulness in any case possible, how 

 close is the tie that binds modern science to modern industry, the ab- 

 stract researches of the student to the labors of the inventor and the 

 mechanic. This, no doubt, is as it should be. The interdependence 

 of theory and practise can not be ignored without inflicting injury on 

 both; and he is but a poor friend to either who undervalues their 

 mutual cooperation. 



Yet, after all, since the British Association exists for the advance- 

 ment of science, it is well that now and again we should choose our 

 place of gathering in some spot where science rather than its applica- 

 tions, knowledge, not utility, are the ends to which research is pri- 

 marily directed. 



If this be so, surely no happier selection could have been made than 

 the quiet courts of this ancient university. For here, if anywhere, we 

 tread the classic ground of physical discovery. Here, if anywhere, 

 those who hold that physics is the true scientia scientiarum, the root 

 of all the sciences which deal with inanimate nature, should feel them- 

 selves at home. For, unless I am led astray by too partial an affection 

 for my own university, there is nowhere to be found, in any corner of 

 the world, a spot with which have been connected, either by their train- 

 ing in youth, or by the labors of their maturer years, so many men 

 eminent as the originators of new and fruitful physical conceptions. 

 I say nothing of Bacon, the eloquent prophet of a new era ; nor of Dar- 

 win, the Copernicus of biology; for my subject to-day is not the con- 

 tributions of Cambridge to the general growth of scientific knowledge. 

 I am concerned rather with the illustrious line of physicists who have 

 learned or taught within a few hundred yards of this building ; — a line 

 stretching from Newton in the seventeenth century, through Cavendish 

 in the eighteenth, through Young, Stokes, Maxwell, in the nineteenth, 

 through Kelvin, who embodies an epoch in himself, down to Rayleigh, 

 Larmor, J. J. Thomson, and the scientific school centered in the Ca- 

 vendish laboratory, whose physical speculations bid fair to render the 



