site logo

Singular Impression On The Visual Nerves By A Luminous Object


If, while sitting in a room, you look earnestly at the middle of a

window, a little while, when the day is bright, and then shut your

eyes, the figure of the window will still remain in your eye, and so

distinct that you may count the panes. A remarkable circumstance

attending this experiment is, that the impression of forms is better

retained than that of colours; for, after the eyes are shut, when you

first discern the image of the window, the panes appear dark, and the

cross-bars of the sashes, with the window frames and walls, appear

white and bright; but if you still add to the darkness of the eyes, by

covering them with your hand, the reverse instantly takes place--the

panes appear luminous, and the cross-bars dark; and by removing the

hand, they are again reversed.



More

;