Anaesthetics are gases (or other substances) which make people unconscious.He was born in 1811 and died in 1870.OF nitrous oxide, Sir Humphry Davy wrote, "It appears able to destroy physical pain. It may be used with advantage during surgical operations in which no great amounts of blood are lost."They are used in operations, and this passage describes some early tests on nitrous oxide (laughing gas) and ether.The passage comes from Sir James Y. Simpson (1896).This man was a famous surgeon and was the author's father."The first experiment," said Sir James Simpson, "of breathing enough vapour to destroy all feeling was made neither in America nor in our own days."A new age in tooth-pulling!""It did not hurt me more than a pin."