"In his landscapes the Spaniard [Diaz] betrays himself.. .Diaz has in him [the painter Theodore Rousseau ] a little of Fortuny. Beside the great genius wrestling for truth and the virile seriousness of Rousseau, beside the gloomy, powerful landscapes of Dupre, with their deep, impassioned poetry, the sparkling and flattering pictures of Diaz seem to be rather light wares. For him nature is a keyboard on which to play capricious fantasies. His pictures have the effect of sparkling diamonds, and one must surrender one's self to his charm without asking its cause; otherwise it evaporates. Diaz has, perhaps, too much of the talent of the juggler. It sparkles as in a magic kaleidoscope. 'You paint stinging-nettles, and I prefer roses', is the characteristic expression which he [Diaz] used to Millet."