gas and air

Joseph Priestley isolated nitrous oxide in 1772, but it was the chemist and inventor, Humphry Davy who, in 1799, wrote a poem about it, having explored what the gas did to him by taking large quantities of it.  Being a scientist as well as a poet he meticulously recorded these experiments.  He then introduced his friends to it – an early recreational drug, you might say, although again he gave it the glow of science by insisting that they describe all their sensations.  Samuel Taylor Coleridge said that mostly he felt like laughing at all those who were looking at him.  This common response gave the gas  its name, laughing gas.  It can also be referred to as happy gas.

 One thing that was clear to those who wanted to turn nitrous oxide from an entertainment into a useful anaesthetic was that if you breathe too much for too long you could asphyxiate yourself. Your lungs filled with the gas which deprived you of oxygen.  So when, in1844, it was used as an anaesthetic in dentistry the nitrous oxide was diluted with oxygen.

 Laughing gas is still used in dentistry.  In the 1930s it was transferred to UK hospitals for use in maternity wards, but in that context it was called gas and air.  Possibly laughing gas or happy gas didn’t have sufficient gravitas for the medical world who wanted an effective and cheap anaesthetic, one that a midwife could administer safely.  As gas and air it can be found in Australian hospitals also.

 Unfortunately, nitrous oxide is a greenhouse gas, 300 times stronger than carbon dioxide in heating the atmosphere.  It has an atmospheric lifetime of 150 years.  This is raising questions about its use.  One solution is to use a scavenging system which takes the nitrous oxide out of the hospital air, with the further refinement that the captured nitrous oxide can be purified and used again.  The other is to find a different anaesthetic.