On January 15, 1784, Henry Cavendish reported that water was composed of hydrogen and oxygen. He had first discovered hydrogen gas and named it inflammable air. At the time of the experiment, Cavendish did not know the existence of oxygen. Oxygen was known as dephlogisticated air, which was thought to be air deprived of phlogistone at that time. Cavendish discovered that water is produced by burning hydrogen in the presence of oxygen. Later on, he also found a 2 to 1 ratio of hydrogen to oxygen.