Hydrolysis of osmium compounds

Abstract

THE chemical determination of the atomic weight of osmium made by Gilchrist1 in 1932 gave the value of 191.5. This result was accepted internationally until Nier2 calculated the value 190.2, now accepted as the international value, from mass spectrographic data. The method used by Gilchrist involved the ignition of ammonium hexabrom- and hexachlor-osmate IV in hydrogen to osmium metal. The ammonium hexahalogenates were crystallized several times from 7 or 10 per cent halogen acid. © 1950 Nature Publishing Group.