Nitrous oxide: Why the environment isn't amused about laughing gas

A young man breathes deeply from a gas-filled bag. He begins to feel a pleasurable sensation "particularly in the chest and extremities" before dancing around and then collapsing in a heap. A few minutes later he comes to and is consumed by a fit of giggles. The young man is a chemist, living in Bristol and his name is Humphry Davy. The year is 1799 and Davy has just discovered the euphoric effects of nitrous oxide (N₂O), which he names "laughing gas."