The colour combinations are frequently the same. Blue and silver, and blue and gold appear most frequently. Then there is brown with gold or silver, and a crepuscule in flesh colour and green, which was also the theme of "On the Balcony."
His subjects were chosen with great discretion. Outside of the "Valparaiso Harbour" picture, a "Southampton Water" and a "St. Marks, Venice," most were devoted to London. There is a Chelsea embankment in winter, a Chelsea in snow and ice, the Westminster Bridge, the Trafalgar Square in snow, and the old Battersea reach and bridge in three versions. Whistler never stopped work at a picture until it was as perfect as he could make it. Many of the pictures that are now on the market, mere scraps and fragments at ridiculous prices, he would not have allowed to go out of his studio. He had the conscience of the true artist, but he never went to the extreme. He knew when to stop, a quality which is exceedingly rare. He would never have spoiled a canvas as Maris and Ryder do. He worked very hard on most of his pictures, but they do not show it. The difficulties and deliberate slowness of execution are lost in the final result. "To say of a picture, as it is often said in its praise, that it shows great and earnest labour, is to say that it is incomplete and unfit for view." He followed this maxim out to the letter. Industry was with him a necessity--not a virtue. Were you to ask me to define the charm of his nocturnes, I should say, I fancy that it lies in the delicious purity of their expression. The emotions which Whistler wishes to excite are those of visional pleasure, of subtle speculation and vague emotional joy. In him inspiration always prevailed over caprice. The picture had first to express the arrangement of colour entrusted to it, and was scarcely allowed any dash or extravagance of brushwork or form, unless they would form a part of his original plan and serve as a contrast or dissonance. He never added anything in his repaintings, but cut out one passage after another; he did not graft on, he pruned, for he meant nothing should remain but the most essential. If there was ever a man tormented by the accursed ambition to put the whole world into one picture, the whole picture into one tonality, and the whole tonality into one colour note, it was Whistler. It is difficult to understand why his work was ever criticized as being unfinished. When Burne-Jones, in a spirit hostile to Whistler's work, declared in the witness box at the Ruskin trial: "In my opinion ... a picture ought not to fall short of what has been for ages considered as complete and finished," Whistler retorted effectively: "A picture is completely finished when nothing more can be done to improve it."
