Color plate illustrates the process of refining sulfur. As seen on the left side of the illustration, crude sulfur is heated over a coal fire which produces a sulfur vapor. This vapor passes into a stone or brick chamber where it condenses on the walls as yellow crystals or a powder referred to as flowers of sulfur. The fire is extinguished after the desired amount of flowers of sulfur are collected.

This plate is from John Howard Appleton's (1844-1930) Chemistry, Developed by Facts and Principles Drawn Chiefly from the Non-Metals, published in 1884. Intended as an introduction to the study of chemistry, this volume contains illustrations throughout the text including color plates. Color plates have been digitized along with a selection of illustrations.