The instantaneous association of colour with sound characterises a small percentage of adults, and it appears to be rather common, though in an ill-developed degree, among children.  I can here appeal not only to my own collection of facts, but to those of others, for the subject has latterly excited some interest in Germany.  The first widely known case was that of the brothers Nussbaumer, published in 1873 by Professor Bruhl of Vienna, of which the English reader will find an account in the last volume of Lewis’s Problems of Life and Mind (p. 280).  Since then many occasional notices of similar associations have appeared.  A pamphlet containing numerous cases was published in Leipsic in 1881 by two Swiss investigators, Messrs. Bleuler and Lehmann.[9] One of the authors had the faculty very strongly, and the other had not; so they worked conjointly with advantage.  They carefully tabulated the particulars of sixty-two cases.  As my present object is to subordinate details to the general impression that I wish to convey of the peculiarities of different minds, I will simply remark—­First, that the persistence of the colour association with sounds is fully as remarkable as that of the Number-Form with numbers.  Secondly, that the vowel sounds chiefly evoke them.  Thirdly, that the seers are invariably most minute in their description of the precise tint and hue of the colour.  They are never satisfied, for instance, with saying “blue,” but will take a great deal of trouble to express or to match the particular blue they mean.  Fourthly, that no two people agree, or hardly ever do so, as to the colour they associate with the same sound.  Lastly, that the tendency is very hereditary.  The publications just mentioned absolve me from the necessity of giving many extracts from the numerous letters I have received, but I am particularly anxious to bring the brilliancy of these colour associations more vividly before the reader than is possible by mere description.  I have therefore given the elaborately-coloured diagrams in Plate IV., which were copied by the artist directly from the original drawings, and which have been printed by the superimposed impressions of different colours from different lithographic stones.  They have been, on the whole, very faithfully executed, and will serve as samples of the most striking cases.  Usually the sense of colour is much too vague to enable the seer to reproduce the various tints so definitely as those in this Plate.  But this is by no means universally the case.

Fig. 68 is an excellent example of the occasional association of colours with letters.  It is by Miss Stones, the head teacher in a high school for girls, who, as I have already mentioned, obtained useful information for me, and has contributed several suggestive remarks of her own.  She says:—­