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.
Explorations of Africa. In the official role of a medical missionary, he set forth to Africa, arriving in Cape Town, South Africa in March of 1841. A few years later, he married Mary Moffat; the couple would have several children.
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.