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"The sulphur is then further purified by heating it in iron vessels (retorts) without access of air, until it is vaporized. the vapor is led into brick-lined rooms. A part of the gas is suddenly cooled and is deposited as a fine powder on the sides of the room. The form is known as flowers of sulphur. Most of the sulphur vapor condenses in the liquid form, and flows down to the outlet of the condensing chamber." -Brownlee 1907

Sulfur Purification

"The sulphur is then further purified by heating it in iron vessels (retorts) without access of air,…