Variety of Hues in the Vegetable Kingdom.

Scientific American 24, 15.6.1861

M. Chevreul, the distinguished French chemist and government dyer, has presented to the Paris Academy of Ciences the eleventh report of his researches on chemistry and dyeing. It consists of two parts: - 1st, New proofs in support of the opinion maintained by M. Chevreul in opposition to many modern chemists, that the phenomena of dyeing are the result, not only of physical adherence, but also of a true chemical affinity; 2d. Of the influence of heat, light, steam, and of the mordant in the process of dyeing. He said it was only at the Hardin des Plantes that he could command complete collections of colors from the three kingdoms of nature, where the director of the School of Botay presented to his examination no less than 15,000 hues of leaves and flowers of all countries.