Misc: What is the substance obtained from acacia trees that is used in medicine?

Questions

B.C. Noah's ark grounded, Mt Ararat (calculated date)?

Alexander Nevsky of Novgorod defeats Teutonic Knights?

Richard Roose boiled to death for trying to poison an archbishop?

Indian princess Pocahontas marries English colonist John Rolfe?

Sir Henry Havelock British soldier (War in Afghanistan 1838-39), born.?