﻿Principles of Molecular Physics. 105 



tances, and inversely proportional to the square of the distance. 

 This may seem probable, but is not self-evident ; and in fact no 

 reason can be assigned why one material point having no extent 

 should act upon another with a force decreasing with the dis- 

 tance, according to any law whatever. The law of inverse 

 squares is a consequence of wave propagation, or of radiations 

 along definite lines, received on a molecule of definite size, and 

 cannot be predicated of a force that acts instantaneously between 

 two mathematical points. To suppose such a law is an arbitrary 

 assumption. 



2. If matter consists of material points, as supposed by Pro- 

 fessor Bayma, it is no more difficult to conceive of an atom of 

 continuous matter than of the space coextensive with it. 



3. It is not more difficult to conceive of an indivisible atom 

 acting as a whole upon another atom w T ith a certain energy, than 

 of a mere point acting upon another point, and causing it to 

 change its place, at the same time transferring to a new point all 

 the properties it possesses. 



4. If the occult nature of the force of action of one material 

 point on another be such that the intensity becomes indefinitely 

 small at indefinitely small distances, instead of infinitely great as 

 imagined by Professor Bayma, then a collection of an infinite 

 number of material points may form one invariable atom, 

 since the size of the atom may in every instance be so inappre- 

 ciable in comparison with the distance between the nearest 

 atoms that there may never be any inequality of extraneous action 

 on different points of the same atom, imparting different velo- 

 cities to them, and so tending to break up the continuity of the 

 matter. Besides, we have already seen that no inequality of 

 elementary action, by reason of a difference of distance, is legiti- 

 mately deducible from Professor Bayrna's premises. 



5. In speaking of atoms of gross matter as u indivisible/' no 

 other ground was intended to be taken than that each atom was 

 indestructible from any possible action of another atom, and es- 

 sentially invariable in form. This does not preclude the idea 

 that the atom may be an aggregation of a finite number of 

 material points; for it may be that the mutual action of two 

 attractive points passes into a repulsion at excessively minute 

 distances, and so that an atom of ordinary matter may be a 

 system of material points in either a statical or dynamical equi- 

 librium. Indivisibility, taken in the only sense in which the 

 term can properly be used, does not, then, necessarily imply 

 continuity, as maintained by Professor Bayma. 



6. The assumption that each atom is " spherical in form," 

 was adopted merely as the simplest embodiment of the funda- 

 mental principles that the action of the atom was equal in all 



