His powers of observation were exceptionally keen. Dr. Toulouse, in the course of an experiment he made with him, placed a photograph of an idiot child before his eyes for a few moments. He immediately noticed certain anatomical peculiarities which as a rule would only strike a medical man, and he noticed them although they were scarcely perceptible in the photograph, which had greatly faded. But, adds Dr. Toulouse, as soon as Zola ceased to observe consciously, his attention flagged, and at times he did not even recognise acquaintances whom he met in the street. "They think," he said to the doctor, "that when I forget to acknowledge them I am absorbed in deep meditation about my next novel, but as a matter of fact I am not thinking of anything." It was the same with his memory. When he wished to remember any object or scene, the details became printed on his mind as clearly and fully as if they had been photographed. But unless he made a voluntary effort, his memory did not serve him. When he was Président de la Société des Gens de Lettres three months elapsed before he could repeat the names of the twenty-four members of the committee. If he had been as deeply interested in those gentlemen as he was in the facts he collected for his books, he would certainly have recalled their names at once. Some novelists note everything around them,--people, places, and occurrences,--and store them up for subsequent use in one or another book; but that was not Zola's system. If he were writing about peasants, other matters scarcely interested him. You might have told him something curious about soldiers or financiers, he would have given it little heed. He isolated his mind, as it were, concentrated it entirely on the subject he had in hand. Moreover, his imagination was as systematic as his memory. As stated in a previous chapter, he first decided on the general ideas he would illustrate, then, by deduction, he imagined the characters likely to illustrate those ideas. A thousand concrete facts thereupon arose in his mind, grouped themselves in his system, and imparted life to his philosophical abstractions. That faculty, that power of assembling affinitive images, tending to a logical end, was preponderant in Zola. By its means the psychical processus is canalised, mental effort and waste are diminished, and the will is able to act in a well-defined manner. In Zola such power was developed to the highest degree, and therein will be found the reason of his intellectual superiority. It links him with all the great creators possessed of systematic minds, the men who have gone, not groping darkly, but with patient effort and in full light, towards their objects. Hugo and Balzac showed by their writings that their brains were organised in the same manner. The quick and inconsiderate mind, so unequal in its inspirations, which is often attributed to artists, does not seem compatible with great creative power, the latter acting in a much more uniform manner.