﻿106 Prof. W. A. Norton on the Fundamental 



directions, and that the attractive action upon an atom of aether 

 was neutralized at minute distances by the resistance developed 

 at the point of contact. The existence of such a resistance 

 necessarily implies that the elementary parts of the attractive 

 atom, whether finite or infinite in number, act repulsively at 

 very minute distances. But another conception may be formed 

 of the mode of operation of an atom of gross matter, which 

 involves no other supposition than that it acts equally outward 

 in all directions from a centre, and takes no account of its geo- 

 metrical extent. This is, that the effective attraction of the atom 

 for the (Ether of space is due to the existence of a repulsion less 

 than would be exerted by the one or more atoms of (Ether that 

 would naturally occupy its place. The result would be the con- 

 densation of an atmosphere of aether around the atom, without 

 the exertion of any direct attractive force, or of any additional 

 force of resistance. We may conceive the molecular atmosphere 

 of electric aether to originate in a similar way; but as the op- 

 portunity of examining and testing this idea sufficiently has not 

 yet been obtained, I shall continue to regard the electric aether 

 as directly attracted by the atom of gross matter, and that the 

 antagonistic force of resistance is furnished by the repulsion of 

 the luminiferous aether condensed around the atom. 



If, in accordance with these views, we seek for a possible 

 origin of gravitation, we can find it in a primary attraction sub- 

 sisting between atoms of gross matter. This must be excessively 

 feeble in comparison with "molecular forces," and modify the 

 effect of those forces only by creating a slight additional pressure 

 of contiguous molecular atmospheres. Should we assume the 

 primary actions between atoms of all kinds to be wholly repul- 

 sive, and the effective attraction of the gross atom for both its 

 aethereal atmospheres to be a mere consequence of inequalities 

 of repulsion, it is conceivable that the attraction of gravitation 

 might result from aethereal waves, as maintained by Professor 

 Challis, these waves having their origin in a dynamical equili- 

 brium of the atmosphere of universal aether condensed around 

 each atom. 



Another critical remark is the following : — 



Again, aethereal substance, according to the author, is repulsive ; 

 now this is inconsistent with astronomical facts, as we have suffici- 

 ently shown. 



The principal astronomical fact here referred to is that the 

 planets do not encounter any sensible resistance in their motion 

 through space. The evidence of an aethereal resistance afforded 

 by Encke's comet, Professor Bayma strives to explain away with- 

 out success. The fact that no sensible resistance is experienced 



