Partial-thickness burns (2nd degree burns)-- affect the top 2 layers of skin. Most notable by blisters (which may develop quickly or take 24 hours to form), but also red, mottled, wet and painful skin. Full-thickness burns (3rd degree burn)-- all three layers of skin affected; leathery, dry, charred, gray.
1 Discoveror: known since ancient times. 2  Place of discovery: not known. 3  Date of discovery: unknown. 4  Origin of name: from the Anglo-Saxon word  gold  (the origin of the symbol Au is the Latin word  aurum  meaning  gold ).
An astronomical unit (AU) is a measure of distance often used in astronomy, equal to the distance between the Earth and the Sun. In terms of more common units of measurement, an AU is equal to about 93 million miles (150 million km), or the distance light travels in a little over eight minutes.