29i D.'s Second Reply to C. 



If a grcalcr violation of common sense, and of the principles of 

 collision themselves, can be adduced than this is, I should be 

 happy to see it, 



A Prop, of this kind I had introduced into my reply (Prop. 

 A.), and had demonstrated it clearly and legitimately. C. has 

 attempted to refute this Prop. — but how ? To invalidate the 

 proof, C. thought it, of course, necessary to quote it. Now this 

 proof consists of five connected dependent periods. C. in his 

 quotation has omitted the first two, lopped off the connec- 

 tive dependence of the third, left out a material part of the 

 fourth, and in toto suppressed the fifth ! ! After having done 

 so much towards the refutation, he quotes from Mr. Herapath, 

 " that all the strokes between perfectly hard bodies have no du- 

 ration and are thence equally smart." From this he infers, 

 what is " undoubtedly" true, that " the strokes are equally 

 smart ivith respect to duration under every momentum." But he 

 goes on, " and consequently it may, with just as much reason, 

 be concluded, that the momenta of the moving bodies have no 

 effect on the intensities of the strokes ;" that is, because the ve- 

 locities have no effect on the duration or time of the strokes, the 

 mometita, he concludes without showing why, have no effect on 

 the iiitensities of the slrokes. This is the result of C.'s pro- 

 found refutation. Certainly its evidence is so clear that the 

 scientific world cannot fail of receiving it with non-resisting ve- 

 neration ; for it is well known the mass drawn into the velocity 

 gives the momentum, and therefore by C.'s new system, I 

 sujipose, the mass drawn into the duration of the stroke, that 

 is, into no time, will give the intensity. I cannot say that this 

 is precisely C.'s method of generating functions ; but as he has 

 manifestly discovered the same relation between the intensity of 

 a stroke and momentum, as between velocity and no length of 

 time, it is natural to conclude that he generates intensity from 

 nothing in the same way as momentum from velocity. Whe- 

 ther this really be the case C. can tell us. I am however in- 

 clined to think, that if he does not give us something like a 

 proof of his inference, the world will be apt to precipitate his 

 pretensions a long way below the zero of mediocrity. 



Having now given, of C.'s efforts to establish and refute, a spe- 

 cimen of each, from which the success and value of the rest 

 may be easily computed, I will briefly advert to his treatment 

 of the quotations I have made from Newton, Playfair, Emer- 

 son, and Hutton. To do this I shall spend no time in com- 

 menting. I shall at once come to facts ; out of which, in order 

 to a further saving of time, I will select one, the perversion of 

 which will sufficiently, and I think satisfactorily, show to what 

 lengths a man may be carried by invention uncontrolled by 



"integrily" 



