The three chief expressive--as distinguished from representative--factors in Wilson’s work are darkness of tone, the scheme of colour, and the quality of the paint. I am inclined to think that the general darkness of Wilson’s pictures is the necessary result of the kind of subjects he treated. The darkness is necessary to tune the mind of the spectator to gloomy and tragic thoughts,--to spread over his mind what Johnson calls ‘a general obscurity of sacred horror, that oppresses distinction, and disdains expression.’ In his worst pictures this darkness of key readily passes into emptiness and blackness; but in his best pictures this darkness ranges through a gamut of subdued and glowing colour, which relieves the gloom and comforts us as it were in our distress. The tone and colour are thus to some extent determined by the character of the objects represented; the tone by their general emotional effect, and the colour scheme as conditioned by the tone, though controlled within rather wide limits by the natural colours of the objects represented. But the third element, the quality of the paint, seems altogether independent of the objects represented. It seems to reveal only the artist’s attitude towards these objects. It is as thoroughly subjective as the emotional vibration in the voice of an excited speaker. Under this term, the quality of the paint, I include all the immediate presentative elements of painting, the thickness or thinness of the impasto, the way the paint is put on, the signs of the brushwork, everything, in short, that tells us how the artist felt towards the objects he was representing. The main object of Turner’s study during the period we are dealing with was the assimilation of the Wilson tradition, his study of the facts of Nature, simply as facts, falling into the second place. For a time the two lines of study are kept distinct. On the one hand, the work of neat and systematic note-taking face to face with nature is continued, and on the other hand, a number of studies aiming at the embodiment of the artist’s subjective attitude make their appearance. The final synthesis of the two factors, the without and the within, is of course only arrived at in the finished work of art, but the contents of the sketch-books of this period fall easily apart, according as they lean either in the direction of the particular facts or in the direction of the emotional synthesis.