John Dalton observed that water could turn into a liquid, solid and a gas. This was because of the particles compositions. Today we now know how the particles react when they are put in certain conditions. For example when water becomes a solid (ice) the particles because close to each other. (jan 1, 1766 – jan 1, 1844)
Added to timeline:
Date:
jan 1, 1766
jan 1, 1844
~ 78 years