Humphry Davy English chemist Davy discovered the anaesthetic effects of laughing gas nitrous oxide In he was appointed lecturer at the Royal Institution where he investigated with his assistant Michael Faraday his theory of volcanic action Using electrolysis Davy isolated the metals barium calcium magnesium potassium sodium and strontium as well as proving that chlorine was a chemical element He wrote on the subject of agricultural chemistry but is probably best known for his invention in of the miners safety lamp which enabled deeper more gaseous seams to be mined without risk of explosion After a portrait by Sir Thomas Lawrence From Chemistry by J Sheridan Muspratt London