Nitrous oxide, N2O; so called from the exhilarating effects it produces when inhaled. (See also GAS sb. 3 d.)
1819. Morn. Chron., 7 April, 3/4. Dr. Thornton … will deliver a Popular Lecture on the Human Frame, and the different Gases, when the Laughing Gas will be exhibited.
1842. Brande, Dict. Sci., etc., Nitrous oxide.… When nitrous oxide is respired, it produces effects somewhat similar to those of intoxication; hence it has been called laughing gas.
1869. Daily News, 2 Jan., 5/5. Protoxide of nitrogen, more commonly called laughing-gas, as an anæsthetic agent.
