Page:Experimental researches in chemistry and.djvu/324

1831.] fig. 14 to represent a fixed circular brush, with long hairs, and the little dots to be the sections of so many wires, forming the arms of a frame which, when turned round, shall carry the hairs of the brush forward a little, and then, letting them go, allow them to return quickly to their first position. If this frame be turned continually round, it would cause the brush, when looked at from a distance, to appear as a revolving toothed wheel, although in reality it had no circular motion. Now, what is performed here by the wire-arms at the outer extremity of the hairs, and the natural elasticity of the latter, may, in the wheel animalcule, be effected at the roots of the fibrillæ by muscular power; and in this or some similar way the animal may have the power of urging the current necessary to supply food, and, at the same time, producing the spectrum of a continually revolving wheel, or even the more complicated forms discovered by Leeuwenhoek (fig. 15), without requiring any powers beyond those which are within the understood laws of Nature, and known to exist in the animal structure. Royal Institution, Dec. 10, 1830.

[In Mr. Whitock's carpet and fringe-manufactory at Edinburgh, they were covering a cord with silk. The cord was of two strands, differently coloured, slightly twisted, and was turning rapidly round on its axis. In many places it looked like a party-coloured cord perfectly still. This was from the continual recurrence of portions different from their neighbours, in the same place; they were not visible all the way round, but only above or below, or in some particular part of their revolution.—July 1833. M. F.]

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In consequence of the necessity I was under of sending the paper (page 291) referred to in the above 'Proceedings' to press by a certain time, I was unable to pursue many of the beautiful combinations of form, colour, and appearance to which the experiments led, especially as they promised only amusement, and little more of instruction than the paper itself contained;