power, which matter possesses, of attracting a ray of light. If Mr. Anderson pours some
Fig. 18.
water, gently and steadily, into the basin, the water will attract the rays of light downwards, and the piece of silver and the sealing-wax will appear to rise up into the sight of those who were before not high enough to see over the side of the basin to its bottom. [Mr. Anderson here poured water into the basin, and upon the Lecturer asking whether any body could see the silver and sealing-wax he was answered by a general affirmative.] Now, I suppose that everybody can see that they are not at all disturbed, whilst from the way they appear to have risen up, you would imagine the bottom of the basin and the articles in it were two inches thick, although they are only one of our small silver dishes and a piece of
