Had a pan of something on the hob this morning and the whole kitchen smelled of it before the water was even hot. That's what a volatile liquid does — it leaves the surface as vapour without much persuading. Ether's the same, only you breathe it. The lungs are a huge wet surface, so the vapour crosses into the blood in a few breaths, and the blood carries it to the brain, where it slips into the fatty membranes of the nerve cells and quietens the signalling. No message gets through to be felt as pain. Meanwhile breathing itself is run from an older, deeper part of the brainstem that's stubborner about being switched off, so at roughly the right dose the chest keeps working while everything else goes quiet. The gap between those two doses is not large, which is the whole art of it.
Morton was a dentist, not a surgeon, and in 1846 he was judging all of that by eye with a glass inhaler. The patient was Edward Gilbert Abbott, and I think his name deserves saying as often as Morton's — he was the one who had to lie down and trust it.
The naming came after the fact, which I always find odd — it was Oliver Wendell Holmes who wrote to Morton a few weeks on suggesting 'anaesthesia', off the Greek for without sensation, and 'anaesthetic' for the agent. A word borrowed from the old philosophers for a thing nobody had been able to do before.
Abbott said afterwards he hadn't felt pain, only a sort of scraping at his neck. Odd thing to be the first person in the world to report.
The inhaler itself was almost embarrassingly simple — a glass globe with a sponge soaked in ether inside and a wooden mouthpiece, made up by a Boston instrument maker. Anything that could be blown, carved or sewn could be repaired by whoever had a bench, which is probably why copies turned up so fast in 1846.