Table 3, J. Sowerby, A new elucidation of colours, 1809.
Table 3, dated Nov. 1, 1807. From James Sowerby (1757-1822), A new elucidation of colours, original, prismatic, and material; showing their concordance in three primitives, yellow, red, and blue; and the means of producing, measuring, and mixing them. With some observations on the accuracy of Sir Isaac Newton. London, 1809.