Diethyl Ether: Soubeiran's One-Operation Still with a Caustic Charcoal Purifier

Soubeiran's apparatus makes fairly pure ether in one operation, as Thorpe's Dictionary (1912) describes it: about 30 lb of sulphuric acid and 20 lb of 85 % alcohol in a copper still, fed with more alcohol from below. A warm condenser takes out steam and alcohol, a vessel of charcoal soaked in caustic soda takes out the sulphur dioxide and oil of wine, and the ether condenses in a cold worm. The best yield comes at 140–145 °C. No flame may reach the ether vapour. The picture: our diagram.