Pigments of flowering plants
A Wisconsin university study of plant pigments from 1913, written by Nellie A. Wakeman and aimed at botanical readers. Its pictures are chemical structural diagrams drawn as hexagonal benzene rings joined by bonds, with element labels such as CH, HC, COH, COCH3, and OCH3 set in plain black line work on a pale ground. A designer could take from them the clean, schematic vocabulary of early organic chemistry diagrams for scientific infographics.
