 Liquid helium was used in great quantity, and one room on the ground floor of the new chemistry building was equipped to recover helium gas from experiments and re-liquefy it.Wallace's main scientific interest was the synthesis and characterization of intermetallic compounds of the rare earths, which include the Lanthanide elements of the periodic table.For this research he assembled a huge team of graduate students and post doctoral associates from many countries, including Argentina, Egypt, India, Japan, Romania, Russia, and China.