General view of the interior of the pot house used for the production of caustic soda at the Dow Chemical Company plant located in Midland, Michigan. Also known as sodium hydroxide, caustic soda was commonly used to produce ethyl cellulose per the process developed by Edgar Britton in Dow's Organic Laboratory. Dow also sold caustic soda for use in the manufacture of soap, lye, rayon, and wood pulp for paper, as well as the refining of petroleum, mineral and vegetable oils, and fats.