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
Chemical tanker smooth and thus easier to clean using permanently fitted tank cleaning machines. Cargo tanks, either empty or filled, are normally protected against explosion by inert gas blankets. Often nitrogen is the inert gas used, supplied either from portable gas bottles or a Nitrogen generator. Most new chemical tankers are built by shipbuilders in Japan, Korea or China, with other builders in Turkey, Italy, Germany and Poland. Japanese shipbuilders now account for the large majority of stainless steel chemical tankers built, as welding stainless steel to the accuracy required for cargo tank construction is a skill which is difficult to acquire.