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XXVIII. Reply to Dr. Ritchie's Remarks. By the Rev, 

 J. W. MacGaulev. 



To the Editors of the Philosophical Magazitie and Journal. 



Gentlemen, 



"VT'OU will oblige me by inserting in your next Number the 

 -^ following reply to Dr. Ritchie's " Remarks" on my paper, 

 given in your Journal for last month. 



I may agree with Dr. Ritchie, that there have been many 

 writers and few readers on electricity and magnetism ; but 

 this seems to be a favourite position of his, if we may judge 

 from the continual effort he makes, as is well known, to prove 

 that almost every writer on the subject has neglected to read at 

 least his experiments; I also admit that the person best able to 

 come forward on the present occasion, has msely left it to 

 others ; and I am greatly mistaken if maturer reflection shall 

 not induce him to believe that he also had done msely in 

 imitating such an example. I did characterize his remarks 

 at Bristol, on the paper which I then read, as hitter and un- 

 called for, because they were intended to deprive me of a 

 claim to originality, and because, like the present, they were 

 unfounded in fact, and irrelevant to the purpose. Should 

 any of the expressions I use appear harsh or uncourteous. 

 Dr. Ritchie will easily pardon me if he recall to his remem- 

 brance some of those he himself has not hesitated to adopt. 

 Your readers are told that my first position, — " The spark and 

 shock obtained from an electro-magnet, on breaking battery 

 communication, are not the spark and shock of the battery, 

 nor of the electro-magnet, but most probably the electricity in- 

 duced on the wire of the helix by the electricity of the bat- 

 tery, or, if it be true that a current passes along the wire, 

 the electricity intercepted in its passage from the copper to 

 the zinc," — is to be found in a paper of his contained in your 

 Number for last June. Though I presume he has placed 

 me in his catalogue of those who write, but do not read, I 

 happen to be very familiar with the few documents he is 

 able to quote. On looking again to the paper he mentions, 

 what do I find ? An account of what he deems an improvement 

 of ^/5 — although many are found who deeni the contrary — on 

 the magneto-electric machine, and a theory which he builds on 

 its results ; but not one word as to whether the spark and shock 

 of an ^Z^c/ro-magnet are derived from the battery or magnet, 

 or any other given source, which is just the thing, and the 

 only thing, my first position contemplates. Besides, in his paper 



