Michel-Eugene Chevreul and his colour classification system

Michel-Eugene Chevreul (1786-1889) made major scientific contributions to t he fields of chemistry and colour. Among other works, he invented a three-d imensional colour classification system, which he used to manufacture a col our atlas showing colour circles and monochrome lightness scales. We have i nvestigated Chevreul's classification system in order to compare it to mode rn standards, We performed colorimetric measurements on the original Chevre ul "Cercles chromatiques" atlas published in 1864, using a spectroradiomete r. The "Cercles chromatiques" are approximately circular (in the a*, b* chr omaticity diagram) and not centered The lightness varies from one sample to another. Gaps or repetitions often occur in the sequence. In the "Gammes c hromatiques," hue angle is constant. Lightness cannot regularly vary on the full scale, because the purely pigmented sample is always at midposition. Several indices suggest that different procedures may have been used in the production of the chromatic circles and the production of the linear scale s of the whole classification system. (C) 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S20-S24, 2001.