MancJiester Memoirs, Vol. xlvii. (1903), No. 11. 29 



still more difificult to appl}-. So far, it has done little 

 or nothing for chemistry ; it has brought forth no 

 discoveries, nor stimulated chemical research ; we can 

 only say that it does not seem to be incompatible with 

 what we think we know. In a certain way it unifies the 

 two opposing conceptions of atomism and plenism, and 

 this may be, after all, its chief merit. 



But there are later theories than that of Kelvin, and 

 some of them are most daring. For instance, Professor 

 Larmor regards electricity as atomic in its nature, and 

 supposes that there are two kinds of atoms, positive and 

 negative electrons. These electrons are regarded as 

 centres of strain in the ether, and matter is thought to 

 consist of clusters of electrons in orbital motion round 

 one another. Still more recently, Professor Osborne 

 Reynolds, in his Rede lecture,* has offered us an even 

 more startling solution of our problem. He replaces the 

 conventional ether by a granular medium, generally 

 homogeneous, closely packed, and having a density ten 

 thousand times that of water. Here and there the medium 

 is strained, producing what Reynolds calls " singular 

 surfaces of misfit " between the normally piled grains and 

 their partially displaced neighbours. These surfaces are 

 wave-like in character, and constitute what we recognise 

 as ordinary matter. Where they exist there is a local 

 deficiency of mass, so that matter is less dense than its 

 surroundings ; and this, as Reynolds has said, is a complete 

 inversion of the ideas which we now hold. Matter is 

 measured by the absence of the mass which is needed to 

 complete a normal piling of the grains in the medium. 

 In other words, it might be defined as the defect of the 

 universe. The " singular surfaces " already mentioned are 



•"On an Inversion of Ideas as to the Structure of the Universe.'" 

 Cambridge, 1903. The Rede Lecture, delivered June loth, 1902. 



