Throughout history, scientists and alchemists have considered different theories about the elements that make up the universe. One of the first theories surrounding the elements was Empedocles’s theory, which stated that there were four basic elements that made up the world around us. These elements included fire, water, earth and air. Since then, we have found that the four ‘elements’ the Empedocles’s theory consisted of, aren’t actually elements at all. Water, for example, is a compound which consists of two elements: hydrogen and oxygen.
For thousands of years, the theory that ‘all matter consists of invisible elements’ have been around as a philosophical idea. In the 19th century, the theory was embraced scientifically