Henry Moseley's Law and it’s Applications

Abstract

Henry Moseley, a British physicist, published data in December 1913 and April 1914 that is now recognised as the first experimental evidence for the atomic number as a physical property of the nucleus. Moseley used x-ray spectroscopy to analyse several rare earth elements provided by Georges Urbain shortly after, in June 1914. Moseley died in the First World War before his conclusions were published. Despite his mother's and colleagues' efforts, a posthumous publication never materialised. The archival materials reveal some of the pressures that could have prevented publication, such as Rutherford's unfamiliarity with Moseley's process, but more importantly, the fact that this data would influence the debate over element 72's discovery. Surprisingly, this controversy is likely to have resulted in the retention of relevant archival material. By tracing the actors who created and curated a specific collection of documents and spectra, one can investigate how rare earth knowledge was produced and verified in the early twentieth century.