TRI168502 "Scientific Researches! New Discoveries in PNEUMATICKS! or An Experimental Lecture on the Powers of Air", cartoon of a lecture at the Royal Institution demonstrating the effects of laughing gas (nitrous oxide) (coloured etching) by Gillray, James (1757-1815); 24.8x35 cm; The Royal Institution, London, UK; (add.info.: experiment conducted by Dr. Thomas Garnett (1766-1802) on Sir John Coxe Hippisley (1748-1825); Humphry Davy (1778-1814) holding a pair of bellows;); 穢 Royal Institution ; English, out of copyright.