REFRACTION
ination of all such as are unessential that the consummate artist shows his calibre. Nevertheless I can recall certain canvases by Corot, poetic masterpieces of the first order, in which the very fullest use of this law was made. It can do no harm at least for any painter to keep the law always in mind, to be used whenever its use will add an element of beauty or of distinction to his work.
In addition to the above defined theory, a long and close study of the law of refraction has left on my mind the strong conviction that the out-worn and rather cheap practice of vignetting was not without a certain sound basis of justification in the underlying laws of nature. If you will bear in mind the fact that the colors and values that are seen out of the corners of the eyes, are, on account of their very situation, able to
[57]
