On the physical lines of magnetic force / Professor Faraday.

  • Michael Faraday
Date:
[1852]
Catalogue details

Licence: Public Domain Mark

Credit: On the physical lines of magnetic force / Professor Faraday. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    be entirely unaffected magnetically, i. <?. it would be a matter of absolute indifference to the needle whether it were moving or still. Matters may be so arranged that the wire when still shall have the same diamagnetic force as the medium surrounding the magnet, and so in no way cause disturbance of the lines of force passing through both ; and yet when the wire moves, a current of electricity shall be generated in it. The mere fact of motion cannot have produced this current : there must have been a state or condition around the magnet and sustained by it, within the range of which the wire was placed ; and this state shews the physical constitution of the lines of magnetic force. What this state is or upon what it depends cannot as yet be declared. It may depend upon the ether, as a ray of light does, and an association has already been shewn between light and magnetism. It may depend upon a state of tension, or a state of vibration, or perhaps some other state analogous to the electric current, to which the magnetic forces are so intimately related. Whether it of necessity requires matter for its sustentation will depend upon what is understood by the term matter. If that is to be confined to ponderable or gravitating substances, then matter is not essential to the physical lines of magnetic force any more than to a ray of light or heat; but if in the assumption of an ether we admit it to be a species of matter, then the lines of force may depend upon some function of it. Experimentally mere space is magnetic; but then the idea of such mere space must include that of the ether, when one is talking on that belief; or if hereafter any other conception of the state or condition of space rise up, it must be admitted into the view of that, which just now in relation to experiment is called mere space. On the other hand it is, I think, an ascertained fact that ponderable matter is not essential to the existence of physical lines of magnetic force- [M. F.] In the Library were exhibited . — Specimen of Auriferous Quartz, Nevada County, California, pre- sented by F. Catherwood, Esq. Portrait of Mr. Faraday, by G. Richmond, Esq. ; and of Dr. Rox- burgh, by J. Z. Bell, Esq. Axe (Marked Stanislaus, 1661), and Ancient Mace. [Exhibited by H. W. Pickersgill, Esq., R.A.] “ Solitude,” designed by J. Lawlor, Esq. and executed by the Messrs. Minton, for the Art-Union of London. [Exhibited by T. S. Watson, Esq., M.R.I.] Specimens of Iron Ore from Northants and of Malachite, from Siberia ;—Black Marble Vases. [Exhibited by Mr. Tennant.]