Oxygen is essential for life. Most every living organism needs it to breathe, even fire needs oxygen to burn.
Invisible, neutral to the taste and with no odour, oxygen is all around us. Present from the time we draw our first breath to when we exhale our last, earth science studies peg the appearance of oxygen in the geological record at somewhere close to 3.5 billion years ago.
Isn't it strange to say, then, that someone discovered it?
This isn't a case of finding something lying on a path and exclaiming "Oh! Look what I found!" and promoting it amongst your friends. There was a keen mind behind the discovery of oxygen, even if, at times, it rambled into impossible hypotheses.
Thanks to Joseph Priestley's genius, we can receive supplemental air in an emergency, we can fuse metal (or cut it) and, after a hard day, we can enjoy a fizzy drink - all without the persecution and ridicule heaped on him by the scientific community and society at large.
Joseph Priestley was an uncommon man. Remarkable for his scientific views (both the legitimate ones and those long debunked) and for his dogged insistence on theism, as well as his pernicious desire to reconcile the two.
But was it really Priestley who discovered oxygen?
To answer that question and understand the man, Superprof takes a closer look.
Joseph Priestley: A Short Biography
Joseph Priestley was born on March 24th 1733, in Yorkshire. Presumably, his mother had a hard time coping with her firstborn so he was sent to live with his grandfather when he was just one year old. Upon his mother's death, he was allowed to return to the family home but, when his father remarried, he was once again sent away, this time to his aunt's.
Wealthy and childless, Aunt Sarah and her husband doted on the boy. She couldn't help but note how intellectually advanced he was so, to cultivate his genius, she sought the best education possible for him. Aunt Sarah wanted him to enter a religious order.
Religion played a pivotal role in Joseph's life.
The family he was born into was Separatist; he was indoctrinated into the Calvinist belief system. His religious beliefs only caused a problem when he became seriously ill. At 16 years old, he seriously believed he should convert to Christianity to save his soul but feared he would not have time to experience conversion before he died.
He survived that illness but his religious convictions took a serious hit. He was barred from becoming a full member of the church and gave up on any idea of joining the ministry. However, as he was already so far along in his religious education, he continued those studies, albeit with a twist.
The book that decided his life's path was Observations on Man, written by David Hartley. This book revolutionised Priestley's thinking about religion, philosophy and psychology. He would dedicate his life to finding scientific proof of religious and moral facts.
To attain that goal, he changed his mind (again), committing himself irrevocably to the ministry.
Was Sir Alexander Fleming just a sloppy housekeeper or was it absent-mindedness that led to his penicillin discovery?
Views on Religion, Philosophy and Politics
For scientists, the more they discover, the less they rely on religion to inform their beliefs. Priestley did the exact opposite: he became a scientist to 'prove' religion. The only trouble was that his beliefs were unacceptable to the laity.
His first assignment, upon graduation from Daventry Academy, was far from palatable. A small country outpost with a congregation outraged by his outlandish religious ideas didn't suit him well. His congregants loathed him and his views. They stopped coming to church and making donations.
Things were getting bad; even his aunt, who had pledged to support him if he joined the ministry, withdrew her support when she discovered he no longer believed in Calvinism.
Three years after his dismissal from his first post, he landed another position. This time, the congregation didn't put so much value on his beliefs - or maybe he hid them better. Whichever the case, he was more productive there.
He established a school - something he'd long hoped to do, and taught classes in natural philosophy. To make lessons more engaging, he bought scientific equipment, outfitting a primitive laboratory. It was there that he wrote his seminal work, The Rudiments of English Grammar.
So effective was this volume at disassociating English grammar from Latin that it caught the attention of academics at the Warrington Academy. He was soon offered a teaching post there, and that's when things really took off for Joseph.
Unlike Rosalind Franklin, who was instrumental in determining DNA's helical structure and virtually ignored during her lifetime, Joseph Priestley's positions were the talk of scientific, religious and political circles.
Priestley's Work: Oxygen Discovery
Warrington, with its academic and intellectual atmosphere, was known as the Athens of the North. Joseph and his fierce intellect soon found himself busier and better received than at any time in his life.
He lectured on anatomy and continued his studies in natural science. Upon his declaration that he would write a book about the history of electricity, colleagues arranged meetings with the top men in that field. During one visit with Benjamin Franklin, he was encouraged to conduct experiments.
That was the start of his experimental work.
By 1774, Priestley had published several books on several topics, ranging from politics to theology, philosophy and history. And, of course, science. So, when the first volume of Experiments and Observations on Different Kinds of Air was published, academics eagerly snapped it up... only to scratch their heads over it.
Some thought it might address questions of physics while others believed it meant for chemists and still others made it out to be a warning for politicians about scientific advances.
Regardless of how it was received, the work outlined several discoveries:
- nitrous oxide (called nitric air, in his work)
- anhydrous hydrochloric acid (marine acid air)
- ammonia (alkaline air)
- nitrous oxide (dephlogisticated nitrous air)
- oxygen (dephlogisticated air)
Dephlogisticated air was completely new to him but, as he was about to tour Europe, he had no time to investigate further.
While in Paris, he repeated the experiment that led to that discovery in the presence of French chemist Antoine Lavoisier, who conducted further experiments into this new 'air'. Meanwhile, back in England, Joseph repaired to his lab to conduct further experiments.
Focusing the sun's hot rays on a block of mercuric oxide - solid at room temperature, he generated a quantity of this air, which he tested on mice. Contrary to his expectations, the mice did not die so he took a few whiffs of it. He found that, not only could he breathe better but that the new 'air' burned better, too.
These discoveries populated the second volume of his Experiments and Observation on Air, prefacing the book with the significance of these discoveries to religion. Ever-methodical in his chronology, he recorded every study hiccup and every puzzlement, leaving the deeper implications of his oxygen discovery for Volume III of his Experiments series. It was published in 1777.
For that reason, it's hard to know exactly who discovered oxygen first.
Both Lavoisier and a Swedish pharmacist named Carl Scheele could claim first discovery - records show that Scheele did indeed isolate the gas first, but he published after Priestley. Lavoisier was the first to describe oxygen as purified air, leaving off mention of phlogiston theory.
Joseph Priestley was given credit for Sheele's discovery, apparently a fairly common happening in science, as one of the world's most renowned scientists, Marie Curie, discovered.
Joseph Priestley's Final Years
Joseph legitimately claimed other discoveries, in particular how oxygen is vital to blood. Lavoisier would later present a paper at the French Academy of Sciences on that very subject; his work is credited with the overthrow of phlogiston theory.
Phlogiston theory: the idea of a fire-like element, contained within combustible elements, that is released during burning.
Joseph Priestley clung to the theory even though it was long disbelieved and now, through Lavoisier's work, totally debunked. That obtuseness cost him the esteem of the scientific community. Once sought out for his brilliant mind, Priestley was now tolerated at best and reviled most of the time.
He and his patron, Lord Shelburne had a falling out. The reasons aren't clear but the effect of it is: no longer welcome in scientific, academic, religious or philosophical circles, and with no more patronage, Priestley had to leave town.
He and his family relocated to Birmingham, where they lived happily for ten years... before having to flee for their lives.
Priestley's dogmatic insistence on his religious and political views did not sit well with the laity, who rose up against him in a terrifying spectacle of mob violence now known as the Priestley Riots. At the urging of friends, the family fled to the United States, where they lived out the rest of their lives.
Unlike other famous chemists and their discoveries, Joseph Priestley's work is renowned in several academic circles, not the least of which are his contributions to English grammar. Indeed, some contend that he is better known for his pedagogy than any scientific achievement.
Still, his brand of philosophy was impactful. Many of his ideas live on in utilitarian philosophy, a doctrine shaped by Herbert Spencer and John Stuart Mill, among others.
Now, discover what Louis Pasteur is famous for besides making milk safe to drink.