In the 16th century, scientists discovered the existence of gases that were different from the air we breath. Paracelsus demonstrated the existence of a highly combustible gas which he called inflammable air. 100 years later, Henry Cavendish studied this and was able to isolate a gas he called Dephlogisticated Air which created humidity, or water droplets, when heated with flammable air. In 1784, Antoine Lavoisier and Pierre Simon Laplace also isolated dephlogisticated air but called it oxygen and worked on the same experiment as Cavendish. They believed it was the reaction between oxygen and flammable air that created humidity and they found the required proportions to create water, which was one third oxygen and two thirds flammable gas. Lavoisier renamed the flammable gas to Hydrogen. In 1800, Anthony Carlisle and William Nicholson studied the effects of electricity on water and noted that it broke down into two separate gases, 2 parts hydrogen and 1 part oxygen. In the late 19th century, water's chemical formula was established as H2O.