In failing health, which composer gave his last public performance in London in 1848, at a benefit for Polish refugees?

Which Chinese dog breed is famous for its blue-black tongue? George Vancouver named which Pacific Northwest peak after a British rear admiral, not for the local weather? Which Muppet, a hapless stand-up comic, is famous for the catchphrase "Wocka wocka"? Harry Truman ended it in the armed forces in 1948, and the Supreme Court ended it in public schools in 1954. What is it? Which "Divine" singer and actress, born December 1, 1945, was named after Bette Davis? Which waterway runs from Colón on the Atlantic side to Balboa on the Pacific side? President James Buchanan feuded bitterly with which Illinois senator from his own Democratic Party? It sounds like it should come from a great white, but a suit made of which worsted or rayon fabric is most likely gray?