Joseph Priestly, not to be confused with Jason Priestly, was an 18th century theologian, natural philosopher, chemist, educator and political theorist.Though the discovery of “soda water” had little scientific value, Priestly called it his “happiest discovery”.

So how did the discovery come about? It was largely due to the fact that in 1767 he: 1) got a new job and 2) moved.

For starters, by getting a new job as a minister he had a lot more free time (to experiment and make discoveries) compared to when he was a teacher. But what was more important was the fact that when he moved to his new town, the official minister’s home was not ready. As a result, he stayed at another house which happened to be located beside a brewery.

Due to his scientific curiosity, it wasn’t long before he began conducting experiments in the brewery. He noticed that the vats of fermenting liquid emitted what he called “fixed” or “mephitic” air (what we call carbon dioxide), and he discovered that if he poured water between two cups over top of the vats, the water became suffused with the “fixed air” and acquired a “fizz”. Within days Priestly was discussing this new invention with colleagues and published a pamphlet describing it: Directions for impregnating water with fixed air, in order to communicate to it the peculiar spirit and virtues of Pyrmont water, and other mineral waters of a similar nature.

Here’s a picture of Priestly’s soda water apparatus:

Priestly was a “compulsive sharer” and he believed in the circulation and dissemination of ideas. So instead of protecting his invention and patenting it, he shared it immediately with everyone. Apparently the notion of withholding information for personal gain was unimaginable to someone like Priestly.  However, as a result of this “compulsive sharing”, a man by the name of Johann Schweppes would eventually patent a method of carbonating water in 1783 and Priestly would forever be dependent on financial patrons.

I learned about this fact from: Johnson, Steven. The Invention of Air A Story of Science, Faith, Revolution, and the Birth of America. River Head Books, New York: 2008. [By the way, a great read, I highly recommend it]