438 Mr. Earnshaw's Reply to Prof. Kelland's Defence 



the Professor point out one link of my argument against New- 

 ton's law which violates this supposition.] I find as a result 

 that there is always one direction in which the particle is 

 urgedfrom its position of rest ; and therefore, as the motion 

 of the particle in that direction could not be vibratory, New- 

 ton's law cannot be the law of molecular force in the lumini- 

 ferous aether. This explanation, I trust, will enable the Pro- 

 fessor to see that he has written his review of my memoir 

 under the influence of a complete misconception of its nature, 

 to which is due the origin of his complaints that some of my 

 reasonings are unintelligible to him, and that the whole line 

 of my argument is inadmissible (August, p. 130), to which 

 charges it is obviously not necessary for me to make any 

 further reply. There is, however, one argument, which though 

 it belongs to this head, I cannot allow to pass without more 

 particular notice, because upon reading it I could not but 

 consider it as a strong indication of the Professor's having al- 

 lowed other motives than " a desire for truth " (Sept. p. 207) 

 to influence him in bringing it forward. It stands in the 

 Magazine for this month (p. 270) in these words: " I will only 

 add, when it is concluded from the hypothesis of a cubical 

 arrangement of the particles, acting by forces which vary ac- 

 cording to the Newtonian law, that the direction of one side 

 of the cube is stable and of one unstable, ought we not to ask, 

 Is it the hypothesis, or the reasoning based on it which is er- 

 roneous? Must it not of necessity be the latter?" Now one 

 would think from the manner in which this argument is brought 

 forward that the matter animadverted upon by the Professor 

 forms a part of my reasoning. Your readers therefore will be 

 surprised to be informed that it stands in my memoir as a 

 purely casual observation, upon which not a step nor even 

 a word of my reasoning against Newton's law depends. 

 Why then did the Professor bring it forward and draw from 

 it the sweeping inference that my reasoning is erroneous ? 

 Unfortunately for the Professor, in this instance he reaps no 

 advantage by stepping out of the line of legitimate argument, 

 as his objection is founded on the misconception that I have 

 supposed the particles to be in equilibrium. 



2. In commencing his reply to my letter printed in your 

 Magazine of July, the Professor calls upon me to state " what 

 I conceive to be the direct effect of matter." I conceive it to 

 be that effect which arises from the supposition that matter 

 and aether act upon each other by attraction or repulsion (en 

 passant, I do not see why I am called upon for this definition, 

 as I have nowhere employed the direct action of matter).' By 

 the indirect action of matter I mean that effect which results 



