I Love to Laugh Mr. Wigg, is said to float because of an excess of "laughing gas", although it is clear that the term is not used in the chemical sense. So-called "laughing gas" (nitrous oxide) was one of the earliest effective anaesthetics developed in the Nineteenth century. it was popularised by dentists, for pain-free tooth extractions, as well as by showground novelty booths. Customers at the booth would be gassed and, as they were recovering from the drugged sleep they often felt euphoric and giggly. Hence the name. A famous 1931 British comedy sketch starring Cicely Courtneidge, called "Laughing Gas", was based on
Inert gas sources rich in this element, through cryogenic distillation or membrane separation. For specialized applications, purified inert gas may be produced by specialized generators on-site. They are often used aboard chemical tankers and product carriers (smaller vessels). Benchtop specialized generators are also available for laboratories. Because of the non-reactive properties of inert gases they are often useful to prevent undesirable chemical reactions from taking place. Food is packed in inert gas to remove oxygen gas. This prevents bacteria from growing. It also prevents chemical oxidation by oxygen in normal air. An example is the rancidification (caused by oxidation) of edible oils.