1540

Diethyl Ether

Paracelsus (1493–1541), Valerius Cordus (1515–1544), Crawford W. Long (1815–1878)

Organic chemists divide compounds into classes based on the arrangements of their atoms. Where the oxygens, sulfurs, nitrogens, and other noncarbon heavy atoms go determines what “functional groups” the compound has, which allows us to infer a good deal about a compound’s properties. One of the simplest classes is the ethers, which have an oxygen atom that looks as if it’s been dropped into the middle of a chain of ordinary carbon-carbon single bonds. You can’t make them by that method (yet), but the German physician and botanist Valerius Cordus discovered in 1540 that when ethyl alcohol is heated up with sulfuric acid (vitriol), diethyl ether is produced. (It’s quite possible that earlier alchemists might have synthesized it, but no solid proof has surfaced.) The chemists of the time had no way of knowing quite what had happened—such details wouldn’t be cleared up for another three centuries or so—but this “sweet oil of vitriol” was clearly a new compound.

Diethyl ether (known familiarly as simply ether today) is a light, low-boiling liquid with a powerful, instantly recognizable smell. The low boiling point lets it produce plenty of vapors even at room temperature, but this property also makes it wildly dangerous around flames, sparks, or even hot surfaces. Ether catches fire like few other substances can, and its heavier-than-air vapors can flow unpredictably along the floor of a room.

In his treatise De naturalibus rebus (c. 1540), Paracelsus noted that sufficient exposure to ether fumes could make chickens unconscious and unresponsive, and it surely wasn’t long before the same effect was observed in humans. By the 1840s, diethyl ether had become the drug of choice at “ether frolics” thrown by medical students, and after the American surgeon Crawford W. Long used it to painlessly remove tumors from a patient’s neck in 1842, it became the first surgical anesthetic—although it was soon replaced by less toxic (and less flammable) compounds.

This eighteenth-century engraving of ether production appeared in the British periodical Universal Magazine. Making or using diethyl ether around an open flame would now be very strongly discouraged!