THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.} 



JANUARY 1856. 



I. On the Action of Non-conducting Bodies in Electric Induction. 

 By Professor Faraday and Dr. P. Riess*. 



THE accorapanyiug letter explains itself. I have received a 

 most kind answer from M. Riess, which I wish added to 

 it. I have altered the English of the answer a little, chiefly in 

 single, small words, and only in those cases where I thought the 

 alteration would make the author's meaning more clear. Certain 

 expressions of M. Riess almost ask for a reply. In respect of 

 these cases, and to remove ambiguity as to my own meaning, I 

 have ventured to add some foot-notes ; but I trust they will be 

 received, not as exciting discussion about hypotheses, but simply 

 in explication (to the reader) of my own view. It is not the 

 duty or place of a philosopher to dictate belief, and all hypothesis 

 is more or less matter of belief; he has but to give his facts and 

 his conclusions, and so much of the logic which connects the 

 former with the latter as he may think necessary, and then to 

 commit the whole to the scientific world for present, and, as he- 

 may sometimes without presumption believe, for future judgment. 



My dear M. Riess, London, Nov. 19, 1855. 



I have only just arrived at the knowledge of a paper written 

 by you on the action of non-conducting bodies in electric in- 

 duction ; for though I had seen it in Poggendorff' s Annalen, 

 I could not read it. A translation has, however, appeared in the 

 Philosophical Magazine for June of this year, vol. ix. p. 401, 



* Communicated by Professor Faraday. 

 Phil Mag. S. 4. Vol. 11. No. 69. Jan. 1856. B 



