The latter quotation is a sample of many that I have; I give it merely as another instance of hereditary tendency.
I will insert just one description of other coloured letters than those represented in the Plate. It is from Mrs. H., the married sister of a well-known man of science, who writes:--
"I do not know how it is with others, but to me the colours of vowels are so strongly marked that I hardly understand their appearing of a different colour, or, what is nearly as bad, colourless to any one. To me they are and always have been, as long as I have known them, of the following tints:--"
A, pure white, and like china in texture.
E, red, not transparent; vermilion, with china-white would represent it.
O, black, but transparent; the colour of deep water seen through thick clear ice.
"The shorter sounds of the vowels are less vivid and pure in colour. Consonants are almost or quite colourless to me, though there is some blackness about M.
"Some association with U in the words blue and purple may account for that colour, and possibly the E in red may have to do with that also; but I feel as if they were independent of suggestions of the kind.
"My first impulse is to say that the association lies solely in the sound of the vowels, in which connection I certainly feel it the most strongly; but then the thought of the distinct redness of such a [printed or written] word as '_great_' shows me that the relation must be visual as well as aural. The meaning of words is so unavoidably associated with the sight of them, that I think this association rather overrides the primitive impression of the colour of the vowels, and the word '_violet_' reminds me of its proper colour until I look at the word as a mere collection of letters.
"Of my two daughters, one sees the colours quite differently from this (A, blue; E, white; I, black; O, whity-brownish; U, opaque brown). The other is only heterodox on the A and O; A being with her black, and O white. My sister and I never agreed about these colours, and I doubt whether my two brothers feel the chromatic force of the vowels at all."
I give this instance partly on account of the hereditary interest. I could add cases from at least three different families in which the heredity is quite as strongly marked.