184-6.] Thoughts on Ray-vibrations. 3G9 



sense, than the matter of this our globe; for matter, according 

 to the assumption, being made up of nuclei and force, the ether 

 particles have in this respect proportionately more of the nucleus 

 and less of the force. 



On the other hand, the infinite elasticity assumed as be- 

 longing to the particles of the ether, is as striking and positive 

 a force of it as gravity is of ponderable particles, and produces 

 in its way effects as great ; in witness whereof we have all the 

 varieties of radiant agency as exhibited in luminous, calorific, 

 and actinic phenomena. 



Perhaps I am in error in thinking the idea generally formed 

 of the ether is that its nuclei are almost infinitely small, and 

 that such force as it has, namely its elasticity, is almost infinitely 

 intense. But if such be the received notion, what then is left 

 in the ether but force or centres of force ? As gravitation and 

 solidity do not belong to it, perhaps many may admit this con- 

 clusion ; but what is gravitation and solidity ? certainly not the 

 weight and contact of the abstract nuclei. The one is the con- 

 sequence of an attractive force, which can act at distances as 

 great as the mind of man can estimate or conceive ; and the 

 other is the consequence of a repulsive force, which forbids 

 for ever the contact or touch of any two nuclei ; so that these 

 powers or properties should not in any degree lead those 

 persons who conceive of the ether as a tiling consisting offeree 

 only, to think any otherways of ponderable matter, except 

 that it has more, and other, forces associated with it than the 

 ether has. 



In experimental philosophy, we can, by the phenomena pre- 

 sented, recognize various kinds of lines of force ; thus there are 

 the lines of gravitating force, those of electro-static induction, 

 those of magnetic action, and others partaking of a dynamic 

 character might be perhaps included. The lines of electric 

 and magnetic action are by many considered as exerted through 

 space like the lines of gravitating force. For my own part, I 

 incline to believe that when there are intervening particles of 

 matter (being themselves only centres of force), they take part 

 in carrying on the force through the line, but that when there 

 are none, the line proceeds through space*. Whatever the 



* Experimental Researches in Electricity, pars. 1161, 1613, 1663, 1710, 

 1729, 1735, 2443. 



