Prof. Norton on Molecular Physics. 195 



we shall follow the indications of existing science, which, as will be 

 generally conceded, point to a dynamical origin of the molecular 

 forces. The ideas we have thus been led to form with regard 

 to the real nature and mode of action of these forces are as 

 follows. 



The molecular forces consist of — 



1. A repulsive action of the electric atmosphere of a molecule 

 exerted primarily upon the electric aether immediately exterior 

 to it. This force of repulsion is made up of recurring impulses, 

 which are propagated in waves through the circumambient elec- 

 tric aether. These impulses fall upon the electric atmospheres 

 of contiguous molecules, and are thence propagated down to the 

 surfaces of the central atoms, and take effect upon these as a force 

 of repulsion. 



2. An attractive action exerted by the central atom of the 

 molecule upon the electric aether surrounding it ; originating a 

 series of successive contractions of this atmosphere, and thus of 

 inward-acting impulses, which are propagated outward and form 

 a set of attractive waves. These are received, like the repulsive 

 impulses, upon the surfaces of contiguous electric atmospheres, 

 and propagated to the central atoms, upon which they take effect 

 as an attractive force. The recurring contractions of the atmo- 

 sphere here supposed do not necessarily imply that the force 

 which produces them acts by impulses, for every such contrac- 

 tion must develope a resistance, which will occasion a subsequent 

 expansion; and, at the same time, recurring expansions should 

 result from the similar impulses propagated from surrounding 

 molecules. The electric atmospheres that envelope the atoms of 

 bodies may accordingly be in a perpetual dynamical condition 

 of alternating contractions and expansions, or of alternating 

 inward and outward movements of their atoms, although the 

 primary forces acting upon these atoms should be continuous in 

 their action. 



But if we confine our attention to the action of a single atom 

 upon its electric atmosphere, it will be seen that the expansions, 

 which of necessity follow the contractions, must be of less extent 

 than the contractions; for a part of the contractile force is ex- 

 pended in impelling a portion of the universal aether compressed 

 upon the surface of the central atom normally outward from this 

 surface. To the extent that this takes place will the contraction 

 of the atmosphere exceed the expansion which immediately fol- 

 lows it, and an effective attractive force be propagated through 

 the surrounding electric aether. We are thus led to recognize 

 the existence of a third molecular force, viz. a force of repulsion 

 originating in the attractive action exerted by the atom of the 

 molecule upon its electric atmosphere. 



