Minot, N. D., Aug. 1, 1906.
To the Editor:
—I wish to make some suggestions in connection with the Stevens' phenomenon, inasmuch as no entirely satisfactory explanation has been given, and with the hope that some element in them will lead to a further understanding of these color changes. I make the following observations on the figures illustrating Dr. George T. Stevens' article in The Journal A. M. A., July 21, 1906:
Fix the eye on one of the red corner blocks in Figure 1, and as the red band disappears the block on which the eye is fixed will be the last to be turned green.
While carrying out No. 1 another phenomenon may be obtained, namely, that all the green squares inside the red band may be converted to red.
It will be found easy to suppress the red band in Figure 1 if the eye is fixed