The Air We Breathe

Written by Paolo Vera and Gabby Rivera

Air. We breathe it every day, yet most people do not know the captivating story of how it was discovered. Oxygen was officially ‘found’ in 1772 but its properties were first observed during the Byzantine Empire, around 2nd century BCE. Over the succeeding centuries, different civilizations had inconsistent ideas about oxygen, making it one the most misunderstood elements on the periodic table. This complex yet vital building block of life eluded scientists for nearly a millenium.

The predecessor of oxygen was a substance known as ‘phlogiston.’ It was discovered by George Stahl, a German scientist. Phlogiston was then believed to be the universal component of fire contained in every combustible object. This theory explained why an object’s mass decreased when burned, as its phlogiston components were lost to the air.

Antoine Lavoisier was introduced to phlogiston while he was in university pursuing a law degree. In 1772, he abandoned law and decided to pursue a career in science. Lavoisier was researching the combustion of phosphorus and sulfur when he realised that the masses of the substances increased upon heating. From that point on, Lavoisier viewed Stahl’s widely accepted theory with suspicion.

Together with fellow scientist, Joseph Priestley, Lavoisier collected a gas, which was free from phlogiston. It increased respiration and caused candles to burn for longer periods of time. In 1779, Lavoisier presented his theory of combustion completely removed of phlogiston to the Royal Academy of Sciences. His theory centered around the gas, which was contained in most acids. Lavoisier called this gas oxygène, after the two Greek words for acid generator.

Today, most modern scientists dismiss the idea of phlogiston as a foolish theory conceived during an unsophisticated era. However, if the idea was so senseless, why was it widely accepted by numerous academics during its time? To be completely objective, we must take into consideration the technological limits of Stahl’s era. With the equipment and knowledge he had access to, Stahl crafted a fairly reasonable explanation for combustion. If we were transported back to the 18th century, would we have ridiculed this discovery? Would we have thought differently?          

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