if the above passage may be traced to the same source, it must be confessed that it is almost the only one of the kind in the treatise from which it is taken.
NOTE D.—Par. 66.
In some of these cases there can be no doubt that Goethe attributes the contrast too exclusively to the physiological cause, without making sufficient allowance for the actual difference in the colour of the lights. The purely physical nature of some coloured shadows was pointed out by Pohlmann; and Dr. Eckermann took some pains to convince Goethe of the necessity of making such a distinction. Goethe at first adhered to his extreme view, but some time afterwards confessed to Dr. Eckermann, that in the case of the blue shadows of snow (74), the reflection of the sky was undoubtedly to be taken into the account. "Both causes may, however, operate together," he observed, "and the contrast which a warm yellow light demands may heighten the effect of the blue." This was all his opponent contended.70
With a few such exceptions, the general theory of Goethe with regard to coloured shadows is undoubtedly correct; the experiments with two candles (68), and with coloured glass and fluids (80), as well as the observations on the shadows of snow (75), are conclusive, for in all these cases only one light is actually changed in colour, while the other still assumes the complemental hue. "Coloured shadows," Dr. J. Müller observes, "are usually ascribed to the physiological influence of contrast; the complementary colour presented by the