M. Niepce de St. Victor has presented a third memoir on Heliochrome, or sun color ing, to the French Academy of Sciences which we will give,in extenso, next week, as it contains much of interest to all Daguerre-otypists. It was mentioned by M. Arago, to the Academy, on the occasion, that it is not by contact, but in the camera, that M. Niepce operates, and that he obtains every color. He likewise noticed a very remarkable fact that M. Niepce has observed in his experiments, and to which he directed the study of philo sophers, namely, that the morning light has a much greater photogenic action than the even ing light. For example, if a prepared plate is exposed from nine o'clock till noon, in the camera, the colored impression will be ob tained in a much shorter time than if the same experiment were made from noon till three o'clock. Moreover, if the pictures are looked at by a strong light, M. Niepce not having yet found the means of fixing them completely, the colors become faint, bud this effect is very perceptible if it is morning, whilst it is almost nothing in the afternoon. At the close ot his remarks, M. Arago used these significant words—mdash;"M. Niepce has resolved the problem —mdash;nothing iurther remains for him to do but to perfect it by the permanent fixing of the colors."
This article was originally published with the title "Daguerreotyping" in Scientific American 8, 22, 172 (February 1853)