Crude Carbolic Acid: Carbolic Oil Washed with Caustic Soda, Lowe's Prescription

Caustic soda pulls the phenols out of coal-tar carbolic oil; acid sets them free again as crude carbolic acid. Charles Lowe's prescription, as given by Lunge (1887): 200 gallons of oil stirred two hours with 30 gallons of soda (sp. gr. 1.34) diluted to 150, settled four hours, the soda liquor neutralised with sulfuric acid in a lead-lined tank. Phenol is poisonous and burns skin. The picture: our diagram of the separation.