Plants, trees, and rocks were not forms summarily observed and clumped together in an arbitrary fashion; for him they were beings gifted with a soul, breathing creatures, each one of which had its physiognomy, its individuality, its part to play, and its distinction of being in the great harmony of universal nature. "By the harmony of air and light with that of which they are the life and the illumination I will make you hear the trees moaning beneath the North wind and the birds calling to their young." To achieve that aim he thought that he could not do too much. As Dürer worked seven times on the same scenes of the Passion until he had found the simplest and most speaking expression, so Rousseau treated the same motives ten and twenty times. Restless are his efforts to discover different phases of the same subject, to approach his model from the most various points of view, and to do justice to it on every side. He begins an interrupted picture again and again, and adds something to it to heighten the expression, as Leonardo died with the consciousness that there was something yet to be done to his "Joconda." Sometimes a laboured effect is brought into his works by this method, but in other ways he has gained in this struggle with reality a power of exposition, a capacity of expression, a force of appeal, and such a remarkable insight for rightness of effect that every one of his good pictures could be hung without detriment in a gallery of old masters; the nineteenth century did not see many arise who could bear such a proximity in every respect. His landscapes are as full of sap as creation itself; they reveal a forcible condensation of nature. The only words which can be used to describe him are strength, health, and energy. "It ought to be: in the beginning was the Power." [Illustration: _S. Low & Co._ COROT. THE RUIN.]