The shadows of the trees in the wood, why are they blue? Ought they not to be dark? Is it really blue, or an illusion? And what is their colour when you see the shadow of a tall trunk aslant in the air like a leaning pillar? The fallen brown leaves wet with dew have a different brown from those that are dry, and the upper surface of the green growing leaf is different from the under surface. The yellow butterfly, if you meet one in October, has so toned down his spring yellow that you might fancy him a pale green leaf floating along the road. There is a shining, quivering, gleaming; there is a changing, fluttering, shifting; there is a mixing, weaving--varnished wings, translucent wings, wings with dots and veins, all playing over the purple heath; a very tangle of many-toned lights and hues. Then come the apples: if you look upon them from an upper window, so as to glance along the level plane of the fruit, delicate streaks of scarlet, like those that lie parallel to the eastern horizon before sunrise; golden tints under bronze, and apple-green, and some that the wasps have hollowed, more glowingly beautiful than the rest; sober leaves and black and white swallows: to see it you must be high up, as if the apples were strewn on a sward of foliage. So have I gone in three steps from May dandelion to September apple; an immense space measured by things beautiful, so filled that ten folio volumes could not hold the description of them, and I have left out the meadows, the brooks, and hills. Often in writing about these things I have felt very earnestly my own incompetence to give the least idea of their brilliancy and many-sided colours. My gamut was so very limited in its terms, and would not give a note to one in a thousand of those I saw. At last I said, I will have more words; I will have more terms; I will have a book on colour, and I will find and use the right technical name for each one of these lovely tints. I was told that the very best book was by Chevreul, which had tinted illustrations, chromatic scales, and all that could be desired.