WAITING] This, then, is the theory of the _dissociation of tones_, which is the main point of Impressionist technique. It has the immense advantage of suppressing all mixtures, of leaving to each colour its proper strength, and consequently its freshness and brilliancy. At the same time the difficulties are extreme. The painter's eye must be admirably subtle. Light becomes the sole subject of the picture; the interest of the object upon which it plays is secondary. Painting thus conceived becomes a purely optic art, a search for harmonies, a sort of natural poem, quite distinct from expression, style and design, which were the principal aims of former painting. It is almost necessary to invent another name for this special art which, clearly pictorial though it be, comes as near to music, as it gets far away from literature and psychology. It is only natural that, fascinated by this study, the Impressionists have almost remained strangers to the painting of expression, and altogether hostile to historical and symbolist painting. It is therefore principally in landscape painting that they have achieved the greatness that is theirs. Through the application of these principles which I have set forth very summarily, Claude Monet arrived at painting by means of the infinitely varied juxtaposition of a quantity of colour spots which dissociate the tones of the spectrum and draw the forms of objects through the arabesque of their vibrations. A landscape thus conceived becomes a kind of symphony, starting from one theme (the most luminous point, _f.i._), and developing all over the canvas the variations of this theme. This investigation is added to the habitual preoccupations of the landscapist study of the character peculiar to the scene, style of the trees or houses, accentuation of the decorative side--and to the habitual preoccupations of the figure painter in the portrait. The canvases of Monet, Renoir and Pissarro have, in consequence of this research, an absolutely original aspect: their shadows are striped with blue, rose-madder and green; nothing is opaque or sooty; a light vibration strikes the eye. Finally, blue and orange predominate, simply because in these studies--which are more often than not full sunlight effects--blue is the complementary colour of the orange light of the sun, and is profusely distributed in the shadows. In these canvases can be found a vast amount of exact grades of tone, which seem to have been entirely ignored by the older painters, whose principal concern was style, and who reduced a landscape to three or four broad tones, endeavouring only to explain the sentiment inspired by it. And now I shall have to pass on to the Impressionists' ideas on the style itself of painting, on Realism.