That colours have a profound psychological effect on human beings is a fact which should be appreciated far more generally than is now the case. Used in small quantities, either in the clothing or in household decoration, the colour red, for instance, is most stimulating, both in the way of helping to overcome depression, and quickening the intellectual processes. But when used in any great amount it tends to over-stimulation, with resultant nerve-strain. According to an English savant, Havelock Ellis, who has made a careful study of the psychology of colours, there are some people so constituted that they become violently excited, fall into convulsions, or faint, if obliged even for a short time to look at anything vividly red. The same effect has been noted from yellow. In one instance, the case of a man operated on at the age of thirty for congenital cataract, it is recorded that “the first time he saw yellow, he became so sick that he thought he would vomit.” And that yellow has a nerve-stimulating effect fully comparable with that of red is curiously indicated by the statement of a friend of mine, a professor in a Western university, who says: “Whenever the day is overcast, or I have to do a piece of work calling for unusual mental exertion, I always wear a red or yellow necktie. I find that either colour has a stimulating effect on my mental processes.” On the other hand, the colour violet appears to have a deadening effect. Another acquaintance, a member of the Harvard University professorial staff, and a well-known psychologist, assures me that the sight of anything violet almost nauseates him, and gives rise to a most depressed feeling. In such a case, however, it may be that the colour is subconsciously associated with some unpleasant occurrence in the earlier life, and that the nausea and depression are merely symbolical manifestations of the presence in the subconsciousness of some memory of this occurrence, concerning which there is no conscious recollection. (This important point will later be discussed in detail.) Of more immediate significance is the fact that violet rays are sometimes used to quiet unruly patients in asylums for the insane, and that the alienist Osburne, after many years’ experience, testifies that “in the absence of structural disease, violet light—for from three to six hours—is most useful in the treatment of excitement, sleeplessness, and acute mania.” Altogether, there is warrant for the assertion that red, yellow, and violet are colours that should not be used overmuch, either in one’s apparel or in the decorating of one’s home. Blue, green, grey, and brown, on the contrary, have psychological qualities that make them particularly desirable for decorative purposes.