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LIV. D.'s Second Replij to C. on Mr. Herapath's Theory. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemex,— My last clearly established, against Mr. Phil- 

 lips's correspondent C, some very inexcusable misrepresenta- 

 tions of Mr. Herapath. Instead of answering these charges can- 

 didly, he has endeavoured to divert the attention of his readers 

 to the twistuig and torturing of some of my expressions for 

 the mere purpose of trying to retaliate. After he has thus con- 

 sumed three or foiu* months, and has carefully compared the 

 whole of my quotations, examined the position of every word, 

 and calculated the propriety of every comma ; he h.as at lengtli, 

 amidst his amplified exaggeration, been obliged to acknow- 

 ledge, in one of his powerful instances, that " as the tone and 

 emphasis of the sentences are changed, rather than the sense, it 

 is not of material consequence ! " 



C, Annals for December, p. 423, says, " How Mr. H. proves 

 * that the intensity of the stroke is the force with which each 

 of the balls is acted on m a direction opposite to that in which 

 it came at the time of the contact,' I am at a loss to discover." 

 " The intensity of the force is ' equal to the sum of the mo- 

 menta' ' widi which both balls come in contact.' " In quoting 

 the substance of the last of these sentences. Annals for May, 

 p. 358, " I observed," C. says, " that tlie intensity of the stroke 

 between tvvo bodies moving towards opposite parts is equal to 

 the sum of their momenta' " Surely nothmg can be plainer or 

 fairer than this quotation, particularly when all I have said in 

 the same paragraph and preceding page be considered ; yet 

 C. in his reply. Annals for September, pp. 207 and 208, flies 

 out into a violent philippic, and declares, because I had not 

 written " equal balls " and " equal momenta" that my quota- 

 tion " is absolutely false" and a " tc/7/i</ misstatement."" When 

 I first read these fearful words, I was surprised at the charge ; 

 but when I came to examine the real groundless foundation of 

 them, 



" Obstupui, steteruntque comae, ct vox faucibus hcesit." 



For it is not the least curious part of this affair, that in the 

 whole paragraph, upwards of a page and a (juarter, which 

 contains C.'s much-injured sentence, he has not once used the 

 term " equal balls " or '^ equal momenta," except in two quota- 

 tions from Mr. Herapalh, both a long way bel()re the sentence 

 in question. So great a reason therefore has C. to complain, 

 that the misrepresentation, if there were any, would have been 

 of Mr. 11. ralher than of himself However, if in this matter 

 wc cannot perceive the justice of C.'s ccunplaint, we must at 



ka^t 



