| Description | Letter from Professor A A Watson FRS of the Deaprtment of Physics and Astronomy, donating the two letters from Blackett and Nishina, explaining the circumstances in which he had found them, and their importance.
"'The letters are interesting because of the speculation from Blackett about alternative decay modes of what is now known as the muon and, not least, because of the poignant last sentence in Nishina's letter, written some 7 days after the outbreak of World War II in which Blackett played such a major role." |