In the chapter on the miseries of genius, the author takes exception to the view expressed by M. Lombroso that the creative inspiration of genius is, at least in some cases, the equivalent of epileptic convulsion. That genius may lead to insanity is true; and M. Arréat admits that remarkable aptitudes have often appeared in a family at the beginning of its degeneracy. But he adds that painters are for the most part healthy, and they show hardly any more singularity than other men may have. He concludes his work with the following words: “Genius makes use of, as we have sufficiently shown, faculties which are common to nearly all men, if they are unequally strong and variously distributed with each. Genius, moreover, in the most elevated sense that it can be understood, is an exception among artists themselves, and even in genius, the meeting together of several happy gifts is exceptional. But it is willingly attributed to all those, whatever may be their art, whose works are able to touch the human cords that vibrate the most profoundly. Painters appear to us to compose a well-marked type among such. The reader has seen the characters of it brought together and discussed in this volume: he will preserve its living image after having closed the book.” This in itself furnishes a sufficient recommendation for the perusal of M. Arréat’s work, which apart from its psychological value, is a perfect mine of gracefully written information about painters and their peculiarities. Ω. PHYSIOLOGIE DE L’ART. By _Georges Hirth_. Traduit de l’Allemand et précédé d’une Introduction par _Lucien Arréat_. Paris: Félix Alcan. 1892. Pp. 247. We have now occasion to review a work on a subject much akin to the preceding—a work which has been translated from the German by the same author, M. Lucien Arréat, and supplied by him with a very interesting introduction. This Introduction is in reality a résumé by M. Arréat of a series of studies by M. Hirth on physiological optics. These studies are of great importance and are classed by the French editor under the three heads of Form, Illumination, and Movement. The first of these comprises the subjects of monocular and binocular vision, the depth and the bilateral enlargement of the visual field, perspective and identical points. Under the head of illumination the effect of the “double bath of light” through the two eyes, the “luminous equation,” and the problems connected with optical measurement are considered.