text: Georges Urbain (12 April 1872 – 5 November 1938) was a French chemist, a professor of the Sorbonne, a member of the Institut de France, and director of the Institute of Chemistry in Paris. Much of his work focused on the rare earths, isolating and separating elements such as europium  and gadolinium, and studying their spectra, their magnetic properties and their atomic masses.  He discovered the element lutetium (atomic number 71). He also studied the efflorescence of saline hydrates.