An Englishman named Joseph Priestley made a discovery 250 years ago that marked the beginning of modern chemistry and continues to have important ramifications today. His remarkable find was, in a word:
Oxygen.
Unlike inventions, which create something new, discoveries acknowledge something that already exists and quantify it to explain its significance. Of course, oxygen has always existed, and its utility to human life is completely independent of the need for explanation. We know exactly what it is, why it is important, and what it actually does.
As the world moved from an age of mysticism to an age of reason, science refused to accept superficial explanations of the world and its environment, and scientists sought to explain how things worked. Previously, the elements that made up the material world were limited to the simplistic: earth, air, fire and water. There is still something charming about rationalizing that everything is made up of some combination of these four things.
Air was hard to define since it basically could not be seen or touched, yet it could be experienced in things as dramatic as wind and as mundane as breath. But modern science refused to be satisfied with something as ephemeral as air and wanted to explore just what comprised air. Scientists asked themselves and their colleagues tough questions because in developing the scientific method, it was critical that observations not be unique to one person or laboratory. Experiments must be duplicatable so that others can confirm a universal discovery to build on it.
Into this rapidly developing and changing world entered Joseph Priestley. As a young man, he showed intellectual prowess, but because he was not a member of the established church, he was denied admission to both Oxford and Cambridge. In modern times, it seems strange that religious affiliation would be such an important admission requirement.
As a dissenter, Priestley’s educational opportunities limited him to less prestigious, but more inquisitive, higher education. He would attend Daventry Academy, which would prepare him primarily for preaching, but his study of theology changed him from accepting religious dogma as an explanation for the natural world and into a “rational dissenter.” He came to see the natural world as part of God’s creation that was to be explored and rationally analyzed in the context of the Bible to gain an understanding of how it worked. In short, his theological views placed an emphasis on scientific discovery as a means to augment faith.
Even though his studies did not include science, as such, he was encouraged to accept a rational world that reflected a Divine Creator. Science became almost a subset of theological study. Gone was the mysticism that accepted the World without inquiry. Now science would become a tool to explain how God acted, supplementing theology to solve questions about the natural world. For Priestley, there was no tension between faith and reason; rather, the Bible and science were studied in combination to explain a rational world order.
Understanding air seemed like an interesting inquiry since defining something that could not be seen was a significant challenge. Priestley would conduct several experiments to capture gases that were in the atmosphere and isolate them with very crude, but nevertheless effective, laboratory instruments. Hard to believe, but two-and-a-half centuries ago, he was able to break down the component parts of air into eight separate gases — one of which was oxygen.
After isolating oxygen to test its properties, Priestly noticed that a candle burned much brighter with only oxygen, and he found that a mouse in a closed container lived much longer with pure oxygen than with regular air. Experimenting upon himself revealed that he felt more energetic when breathing oxygen.
He would write papers explaining his experiments and engage in debates with other scientists over the interpretation of what oxygen was and how it could be used. His inquisitive mind would get the best of him when he became an advocate for both the American and French revolutions. In his view, the old regimes had to be destroyed to accelerate a scientific, utopic millennium. These ideas did not sit well with his community, and so it was that rabble rousers burned Priestley’s church along with his house and adjoining laboratory. His non-conformist views were not welcomed any more.
Priestley decided that if the old world would not appreciate him, he would leave England and ply his ideas in America. Thus, he moved his family to Philadelphia, where he was re-acquainted with Benjamin Franklin. He found America to be much more welcoming and more tolerant of both his religious beliefs and scientific ideas.
Making fast friends with other leading figures of the day, including Thomas Jefferson, he was an active member of Philadelphia’s Philosophical Society. In America, he would isolate carbon monoxide and continue to write and inquire about the natural world. Many of his discoveries were accidents, and he never had the presence of mind to patent his ideas to monetize his brilliance. Looking over his achievements, he discovered some things as mundane as using Indian rubber as an eraser and making carbonated beverages with carbon dioxide.
Priestley’s curious mind never stopped seeking answers by experimentation and testing ideas. His death at age 71 would finally end his inquiries into the natural world. One hundred years after his discovery of oxygen, a meeting of scientists to reflect on his life and achievements resulted in the founding of the American Chemical Society.
Joseph Priestley’s discovery of oxygen was the beginning of a better understanding of the chemical elements that make up the natural world, but his beliefs were a threat to the old order, which was happy to accept an unexamined life and ignore a better understanding of the creation. His persecution would lead him to realize that America, with its freedoms of religious liberty and expression, was the ideal place for an inquiring mind to push the boundaries of discovery, unfettered by ideology, religious, scientific, or otherwise.