Diethyl Ether: Alcohol Dropped into Sulphuric Acid at 130–140 °C (Boullay's Continuous Method)

Ether is made from alcohol and sulphuric acid. In Boullay's continuous method, as Thorpe's Dictionary (1912) gives it, alcohol drips steadily into hot acid at 130–140 °C and ether distils off, while the acid is re-formed and keeps working. No open flame: the vapour risks exploding if it meets a flame, so the retort is heated by a steam coil. The distillate is washed with milk of lime and rectified; ether boils at about 35 °C. The picture: our diagram.