Page:Memoirs of the Geological Survey of Great Britain, Volume 1.djvu/449

436 duced by Professor Faraday, whose results are strikingly confirmed by those which I have obtained by a mode of experimenting totally different, from that adopted by that talented philosopher. A magnetic curve means, "that exercise of magnetic force which is exerted in the lines usually called magnetic curves, and which equally exist as passing from or to magnetic poles, or forming concentric circles round an electric current A diamognetic curve means a curve formed by a body (diamagnetic) "through which lines of magnetic force are passing," and which do not in any way accord with the ordinary curves produced by sprinkling of iron filings over or around the poles of a magnet. Thus the curves represented in Fig. 1 are true magnetic curves, such as are given by iron filings, shewing the circulation of lines of force between and towards either pole.

With the hope of rendering intelligible the difference between the magnetic and the dia-magnetic curves Fig. 2 is given, in which the two orders of curves are shewn, a and b, in a, representing the magnetic curve lines of connecting circulation; a and b in b, shewing the tendency of other than magnetic bodies to arrange themselves at right angles to the ordinary lines of magnetic direction.