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VII. Experimental Researches in Electricity . — Twenty-third Series. By Michael 
Faraday, Esq., D.C.L., F.R.S., Fullerian Prof. Chem. Royal Institution, Foreign 
Associate of the Acad. Sciences, Paris, Ord. Boruss. Pour le Merite, Eq., Memh. 
Royal and Imp. Acadd. of Sciences, Petershurgh, Florence, Copenhagen, Berlin, 
Gottingen, Modena, Stockholm, Munich, Bruxelles, Vienna, Bologna, 8^c. &;c. 
Received January 1, — Read March 7 and 14, 1850. 
§ 29. On the polar or other condition of diamagnetic bodies. 
2640. Four years ago I suggested that all the phenomena presented by diamag- 
netic bodies, when subjected to the forces in the magnetic field, might be accounted 
for by assuming that they then possessed a polarity the same in kind as, but the re- 
verse in direction of, that acquired by iron, nickel and ordinary magnetic bodies 
under the same circumstances (2429. 2430.). This view was received so favourably by 
Plucker, Reich and others, and above all by W. Weber=^, that I had great hopes it 
would be confirmed ; and though certain experiments of my own (2497.) did not in- 
crease that hope, still my desire and expectation were in that direction. 
2641. Whether bismuth, copper, phosphorus, &c., when in the magnetic field, are 
polar or not, is however an exceedingly important question ; and very essential and 
great differences, in the mode of action of these bodies under the one view or the 
other, must be conceived to exist. I found that in every endeavour to proceed by 
induction of experiment from that which is known in this department of science to 
the unknown, so much uncertainty, hesitation and discomfort arose from the unsettled 
state of my mind on this point, that I determined, if possible, to arrive at some experi- 
mental proof either one way or the other. This was the more needful, because of the 
conclusion in the affirmative to which Weber had come in his very philosophical 
paper; and so important do I think it for the progress of science, that, in those im- 
perfectly developed regions of knowledge, which form its boundaries, our conclusions 
and deductions should not go far beyond, or at all events not aside from the results 
of experiment (except as suppositions), that I do not hesitate to lay my present 
labours, though they arrive at a negative result, before the Royal Society. 
2642. It appeared to me that many of the results which had been supposed to in- 
dicate a polar condition, were only consequences of the law that diamagnetic bodies 
tend to go from stronger to weaker places of action (2418.) ; others again appeared to 
have their origin in induced currents (26. 2338.); and further consideration seemed 
* Poggendorff’s Annalen, January 7, 1848, or Taylor’s Scientific Memoirs, v. p. 477. 
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