The two æsthetic qualities requisite for success in painting are obviously a sense of form, and a sense of colour; without a natural appreciation of the beauty inhering in each of these, the highest technical skill, however valuable, does not suffice. After what you have heard about Greek architecture and sculpture, I need not say another word to show that in the sense of form the Greeks were supreme and unapproachable. But what about their sense of colour? On this the evidence is not so clear and has given rise to divers interpretations. First of all, the Homeric poets, in their vivid pictures of old Greek life, are singularly vague and confused in their words for colour, so much so that people used to imagine that the poet, because he was blind, or the poets, because they were primitive, had no distinct colour-sense. I remember this latter view being pressed upon me by Mr. Gladstone in conversation, together with the reply he had from Charles Darwin, which he gave me to read, that as even insects are guided by a very clear sense of colour, it was absurd to say that the most primitive men should not possess it. This argument seamed both to him and to me hardly conclusive, for the faculties which are now human need not have developed at the same rate from lower forms, or kept abreast of one another in acuteness. Thus human development might not require an acute sense of colour, while that of the insect made it essential, and so lower forms of life might be infinitely more developed in some respects than those far higher in the general condition of their senses and their intelligence. I therefore took another line in my objection: that we know the Egyptians, centuries before the oldest date allowed for Homer, had at least ten distinct names for colour. And this was not because they felt the difference more distinctly, but because in their arts and crafts they produced the varied shades, and therefore found names for them. Even nowadays, it is not the poet, or even the artist, that invents names for subtle shades of colours, but the milliner or the modiste. When I was young, there were two shades of grey known in the phraseology of these people--one as _gris de souris_, the other as _gris de souris poursuivie_. This is but a more minute subdivision of our sensations of colour invented by those that produce it for trade purposes. The want of names for colours is therefore not confined to the Greeks. More important is the fact that their early painters are known to have used but a few and primary colours, and also the further fact that their temples, which they always coloured (and, to my mind, rightly) for effect, were adorned on a simple and primitive plan,--red, blue, white, yellow, being, so far as I know, the colours generally used.