Principles of Molecular Physics. 37 



perty, since it is nothing but position. If it be urged in reply 

 that the points supposed are not mere mathematical points, but 

 also centres of force, the answer is, if the possibility of mere cen- 

 tres of emanation of force be admitted, still to suppose that one 

 centre of force acts upon another is to suppose that one force 

 acts directly upon another force, or that the principle of acti- 

 vity acts upon itself. Again, mobility cannot be predicated of a 

 point, since a force cannot impart motion to nothing, nor to an- 

 other force or collection of forces in a point. This reasoning 

 may not be deemed conclusive ; but the real question here is, not 

 whether it is conclusive or not, but whether it is not as much 

 entitled to be called so as the " demonstration " we find on 

 page 28 of the ' Molecular Mechanics/ that " the hypothesis 

 that bodies are made up of particles materially continuous leads 

 to an absolute impossibility of communication of motion," or as 

 the demonstration on page 30, that " matter cannot be conti- 

 nuous/' 



If it should be urged that we cannot conceive of an atom of 

 which every point does not possess the same activity as every 

 other point, or that the entire space occupied by an atom should 

 alone determine the definite power which it exerts outwardly and 

 receives, it is equally impossible to conceive of mere points en- 

 dued with all the essential properties and powers that belong to 

 matter (these powers differing in intensity and kind, although 

 belonging to mere points), resisting change of place with vary- 

 ing degrees of inertia, and retaining the same activities as they 

 shift their position from one point of space to another. We may 

 as well frankly admit that in all such attempts to reach true 

 conceptions we are vainly striving to sound the fathomless depths 

 of the unknown. 



Another of Professor Bayma's fundamental principles is, that 

 simple elements act at all distances according to the inverse ratio 

 of the squares of the distance. This principle may be admitted 

 as the law of elementary action if w r e regard such action as a pro- 

 pagated emanation ; and it may be adopted as an hypothesis if 

 we conceive, with Professor Bayma, that such action is instanta- 

 neous at all distances; but he undertakes to demonstrate its 

 truth by both " metaphysical and mathematical reasoning.'''' The 

 demonstration, whatever may be said of the metaphysics, is open 

 to this fatal objection — that it involves the conception that gra- 

 vitation and molecular attraction are but the same elementary forces 

 operating at different distances. To show that this cannot be true, 

 let us suppose a primitive molecule posited at the distance (d) 

 from a certain point of the earth's surface, at which the attrac- 

 tion of adhesion becomes sensible; and let us conceive the 

 earth's surface to be perfectly smooth and spherical. Now New- 



