what did chadwick identify?
Neutron
contradiction
 Chadwick was still in Germany at the start of the First World War , and was interned in the Ruhleben internment camp near Berlin , where he was allowed to set up a laboratory in the stables and conduct scientific experiments using improvised materials such as radioactive toothpaste . With the help of Charles Drummond Ellis , he worked on the ionisation of phosphorus , and the photochemical reaction of carbon monoxide and chlorine . He was released after the Armistice with Germany came into effect in November 1918 , and returned to his parents ' home in Manchester , where he wrote up his findings over the previous four years for the 1851 Exhibition commissioners . 

neutral
 In 1925 , Chadwick met Aileen Stewart @-@ Brown , the daughter of a Liverpool stockbroker . The two were married in August 1925 , with Kapitza as Best Man . The couple had twin daughters , Joanna and Judith , who were born in February 1927 . 

neutral
 Chadwick dropped all his other responsibilities to concentrate on proving the existence of the neutron , frequently working late at night . He devised a simple apparatus that consisted of a cylinder containing a polonium source and beryllium target . The resulting radiation could then be directed at a material such as paraffin wax ; the displaced particles , which were protons , would go into a small ionisation chamber where they could be detected with an oscilloscope . 

contradiction
 By early 1945 , Chadwick was spending most of his time in Washington , D.C. , and his family relocated from Los Alamos to a house on Washington 's Dupont Circle in April 1945 . He was present at the meeting of the Combined Policy Committee on 4 July when Field Marshal Sir Henry Maitland Wilson gave Britain 's agreement to use the atomic bomb against Japan , and at the Trinity nuclear test on 16 July , when the first atomic bomb was detonated . Inside its pit was a polonium @-@ beryllium modulated neutron initiator , a development of the technique that Chadwick had used to discover the neutron over a decade before . William L. Laurence , the New York Times reporter attached to the Manhattan Project , wrote that " never before in history had any man lived to see his own discovery materialize itself with such telling effect on the destiny of man . " 

contradiction
 Chadwick became a Fellow of Queens ' College , Cambridge , with his appointment as Chaplain in 1946 , and in 1950 advanced to the position of Dean . His rising academic reputation was confirmed in 1953 with the publication of a project had occupied him since the days of his curacy — his new translation of Origen 's Contra Celsum , with introduction and notes . He had by now made himself an expert in Patristic Greek ; only an inexactness in philology marking his earlier abandonment of Greek for music . Also in 1953 he was appointed co @-@ editor ( with Hedley Sparks ) of the Journal of Theological Studies and continued editing it until 1985 . He held the university appointment of Hulsean Lecturer from 1954 – 6 . 
