Baron von Osten Sacken, of whom I have already spoken, writes:—­

“The localisation of numerals, peculiar to certain persons, is foreign to me.  In my mind’s eye the figures appear in front of me, within a limited space.  My peculiarity, however, consists in the fact that the numerals from 1 to 9 are differently coloured; (1) black, (2) yellow, (3) pale brick red, (4) brown, (5) blackish gray, (6) reddish brown, (7) green, (8) bluish, (9) reddish brown, somewhat like 6.  These colours appear very distinctly when I think of these figures separately; in compound figures they become less apparent.  But the most remarkable manifestation of these colours appears in my recollections of chronology.  When I think of the events of a given century they invariably appear to me on a background coloured like the principal figure in the dates of that century; thus events of the eighteenth century invariably appear to me on a greenish ground, from the colour of the figure 7.  This habit clings to me most tenaciously, and the only hypothesis I can form about its origin is the following:—­My tutor, when I was ten to twelve years old, taught me chronology by means of a diagram on which the centuries were represented by squares, subdivided in 100 smaller squares; the squares representing centuries had narrow coloured borders; it may be that in this way the recollection of certain figures became associated with certain colours.  I venture this explanation without attaching too much importance to it, because it seems to me that if it was true, my direct recollection of those coloured borders would have been stronger than it is; still, the strong association of my chronology with colour seems to plead in favour of that explanation.”

Figs. 66, 67.  These two are selected out of a large collection of coloured Forms in which the months of the year are visualised.  They will illustrate the gorgeousness of the mental imagery of some favoured persons.  Of these Fig. 66 is by the wife of an able London physician, and Fig. 67 is by Mrs. Kempe Welch, whose sister, Miss Bevington, a well-known and thoughtful writer, also sees coloured imagery in connection with dates.  This Fig. 67 was one of my test cases, repeated after the lapse of two years, and quite satisfactorily.  The first communication was a descriptive account, partly in writing, partly by word of mouth; the second, on my asking for it, was a picture which agreed perfectly with the description, and explained much that I had not understood at the time.  The small size of the Fig. in the Plate makes it impossible to do justice to the picture, which is elaborate and on a large scale, with a perspective of similar hills stretching away to the far distance, and each standing for a separate year.  She writes:—­

“It is rather difficult to give it fully without making it too definite; on each side there is a total blank.”