﻿Principles of Molecular Physics. 353 



that Professor Norton proves that his fundamental doctrine is 

 not an " arbitrary assumption" and deserves the name of "esta- 

 blished truth"? 



What he says about the " size " of his atom is directed against 

 an argument by which I proved the impossibility of imparting 

 motion to a globule of continuous matter (Molecular Mechanics, 

 pp. 28, 29). Of course, if the size of the atom were smaller 

 than any assignable finite size, my argument would cease to be 

 applicable : but then such an atom would be a mere material 

 point, and gross matter an unreality and an empty name. But, 

 if the size of Professor Norton's atoms remains finite, my argu- 

 ment remains unanswered. For there will be a finite amount 

 of inequality in the intensity of the extraneous actions (espe- 

 cially molecular) on different points of the same atom, impart- 

 ing to them velocities, the difference between which will be 

 finite and appreciable, and so " tending to break up the conti- 

 nuity of matter." 



In my { Molecular Mechanics ' I had given (pp. 30, 31) a se- 

 cond and, I think, very conclusive proof of the impossibility of 

 continuous matter. The learned Professor says nothing of it, 

 probably because he thought it to consist of what he had pre- 

 viously called " unsubstantialities." Yet the more unsubstan- 

 tial, the easier should have been the task of its refutation. 



As to his saying " We have already seen that no inequality 

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

 legitimately deducible from Professor Bayma's premisses," the 

 reader needs not to be informed that this is one out of the many 

 gratuitous assertions to which the learned Professor has already 

 accustomed us. He does not even take care to make his as- 

 sertion credible. He says " We have already seen," and speaks 

 of my " premisses," when no premisses have been quoted by 

 him, and therefore nothing could possibly have been seen to be 

 either legitimately or illegitimately deducible from them. 



The fifth answer of my American critic dwells on the word 

 " indivisible," which I understood to convey the notion of abso- 

 lute indivisibility. He does not admit my interpretation. He 

 says: 



" In speaking of atoms of gross matter as indivisible, no other 

 ground was intended to be taken than that each atom was inde- 

 structible from any possible action of another atom, and essentially 

 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 extremely minute distances, and so that an atom of or- 

 dinary matter may be a system of material points in either a statical 

 pr dynamical equilibrium. Indivisibility, taken in the only sense 



Phil. Mag. S. 4. Vol. 37. No. 250. May 1869. 2 A 



