The Willamette Valley was green and fertile, a nice after-image on the following afternoon as the plane lowered over the brown Maine woods and the steely blue Atlantic.

I visualise with effort; I am peculiarly inapt to see "after-images," "phosphenes," "light-dust," and other phenomena due to weak sight or sensitiveness; and, again, before I thought of carefully trying, I should have emphatically declared that my field of view in the dark was essentially of a uniform black, subject to an occasional light-purple cloudiness and other small variations.

CALDWELL, ERSKINE. After-image.

CALDWELL, ERSKINE. After-image.

But overwork, poverty, and an eye-trouble produced by his observations on after-images in the retina (also a classic piece of investigation) produced in Fechner, then about thirty-eight years old, a terrific attack of nervous prostration with painful hyperaesthesia of all the functions, from which he suffered three years, cut off entirely from active life.

When I hear a bell-stroke and, as life flows on, its after-image dies away, I still hark back to it as 'that same