Chadwick's toolbox, c 1932.
© Science Museum / Science & Society Picture Library
James Chadwick's toolbox was an old Rhodian cigarette carton in which he kept apparatus used in his scientific work, particularly during his discovery of the neutron. Chadwick (1891-1974) used the pieces of paraffin wax in his neutron detector, while the silver and aluminium foils of different thickneses were used as barriers to help ases the strength of radiation. Chadwick's discovery of the neutron helped to rewrite existing beliefs concerning what was contained in the nucleus of an atom.