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XXXVII. Reply to Prof. TyndalPs Remarks on a paper on 

 " Energy" in < Good Words.' By P. G. Tait, M.A., F.R.S. E., 

 Professor of Natural Philosophy in the University of Edinburgh. 



My dear Sir David Brewster, 



AS an Editor of the Philosophical Magazine you are doubtless 

 aware that Prof. Tyndall has, in the last published Number 

 of that journal, taken exception to certain portions of an article 

 on " Energy," published by Prof. Thomson and myself in e Good 

 Words * in October 1862. We feel that Prof. TyndalPs remarks 

 cannot be allowed to pass without a reply, although we are most 

 unwilling to introduce into the pages of the Philosophical 

 Magazine matters directly personal to individuals. I shall 

 therefore, as Prof. Thomson has requested me to reply for him 

 as well as for myself, proceed to consider Prof. TyndalPs obser- 

 vations as briefly as I possibly can. 



I think it right at starting to call Prof. TyndalPs attention to 

 the fact that, in the Philosophical Magazine (1862, second half- 

 year, p. 65), he has published the following words : — "I do not 

 think a greater disservice could be done to a man of science than 

 to overstate his claims : such overstatement is sure to recoil to 

 the disadvantage of him in whose interest it is made," — and to 

 remind him that any unpleasant results which may follow from 

 the course he has pursued are, by his own acknowledgment, to 

 be laid to his charge. 



First, then, as to the medium in which our article appeared, 

 and the grave offence of putting two names to it instead of one. 

 A journal which contains in nearly every Number a scientific 

 paper by yourself, Forbes, Herschel, or Piazzi Smyth, can surely 

 not be regarded as unsuitable for a paper on "Energy." I first 

 saw a report of Prof. TyndalPs lecture (with its extraordinary 

 statements regarding Mayer) in the pages of the { Illustrated 

 London News ' and the ' Engineer/ I am not aware that these 

 are journals specially employed by scientific men for the judicial 

 discussion of recondite points in science or its history ; nor can 

 I consider a Royal Institution audience as a body qualified to 

 decide upon such questions. An evident consequence of Prof. 



1862), " These facts/' of the'coincidence of dark and bright lines, " re- 

 mained altogether barren of consequences, as far as regards the explana- 

 tion of the phenomena, except to a few bold minds, such as Angstrom, 

 Stokes, and "William Thomson ; the latter two of whom, combining this 

 fact with an ill-understood experiment of Foucault's made in 1849, fore- 

 saw the conclusions to which they must lead, and expressed an opinion 

 which subsequent investigations have fully borne out. Clear light was, 

 however, thrown upon the subject by Kirchhoff in the autumn of 1859, 

 &c."— H. E. R.j 



