December 6:
(1778) French chemist and physicist Joseph Louis Gay-Lussac is born. He co-discovered that water is made of two hydrogen atoms and one oxygen atom, he recognized iodine as a new element, and co-discovered boron.
(1967) The first human heart transplant in USA is performed by Adrian Kantrowitz.
(2006) NASA reveals photographs which suggest the presence of liquid water on Mars.
 French chemist and physicist Joseph Louis Gay-Lussac is born. He co-discovered that water is made of two hydrogen atoms and one oxygen atom, he recognized iodine as a new element, and co-discovered boron.){kind=link}