First identified in the 17th century, oxygen is a gaseous, non-metallic element that makes life possible. The chemist and physician John Mayow proved that oxygen was critical to lifeforms, and could be removed by a naked flame and respiration. A key indication of oxygen's supreme importance was realized when researchers demonstrated that mice could survive longer in air heated by mercury oxide rather than air heated by using a flame [which consumes oxygen]. They were able to prove that the depletion of "eminently breathable air," later termed oxygen, directly resulted […]
