This statement is FALSE. Mercury was not first discovered in the sun. In fact, mercury or quicksilver was discovered by ancient Indians and Chinese even before 2000 BC. Its ores that are called cinnabar are used in traditional Chinese medicines. However, the effectiveness is not yet justified because of the toxicity of the element. Mercury is also used with thermometers both in clinical and lab uses. Nowadays, the use of it in thermometers is gradually disappearing because of its harmful properties.