The primary function of the thyroid is the production of the iodine-containing thyroid hormones, triiodothyronine (T3) and thyroxine (T4) and the peptide hormone calcitonin. 1  T3 is so named because it contains three atoms of iodine per molecule and T4 contains four atoms of iodine per molecule.
David Livingstone was born on March 19, 1813, in Blantyre, South Lanarkshire, Scotland, and grew up with several siblings in a single tenement room.
July 1555: a small group of Africans from Shama (modern Ghana) described as slaves are brought to London by John Lok, a London merchant hoping to break into the African trade. 10 November 1555: a group of Norman and Breton sailors, under the command of Nicolas de Villegagnon, found the first French colony in South America.