A number of years ago Gladstone theorized—from the poverty of words indicating color in ancient Greek literature—that the color sense, as we now possess it, is a comparatively late acquisition. His view was strongly combated at the time and has not since received any general acceptance. It is, of course, impossible to say just what color vision the Homeric Greeks possessed, and we have perhaps no modern races exactly corresponding to them in social and intellectual development.
We have, however, some facts that may be considered as favoring Gladstone's theory; we know, for example, that certain refinements of sensation are cultivatable, and there is some testimony that in some of the lower races the special sensibility in one way or another is not exactly the same as with the more civilized races. Accurate psychometric studies of savages have hitherto been largely lacking, but attention has been directed to the need,