Stephen Hales was the sixth son and one of twelve children born to a prosperous family in England. He studied for the clergy but also studied mathematics and natural sciences. He was ordained as a Priest in the Church of England and remained at his first assigned parish for the rest of his life.
While serving as a religious leader, Stephen was also a versatile scientist. His studies on the circulation of blood were so significant that they were cited in a Nobel Prize presentation 240 years later. He was the first person to perform catheterization of the heart in a living animal.
He performed a number of important studies on plants. Throughout his studies, he also became an inventor of the equipment necessary to obtain the measurements needed for his research. He is generally given credit for inventing the first device to measure blood pressure.`
Other notable medical achievements included a ventilator for improved breathing, a device for the removal of bladder stones, a gauge for measuring the depths of oceans, a method for preserving food, and ideas for baking.
In addition to his breakthroughs, he also laid the groundwork for other scientists including Antoine Lavoisier, the discoverer of oxygen, and Henry Cavendish, the discoverer of hydrogen. In addition, he had an early theory that led to the understanding of photosynthesis in plants.
As a person of faith, Stephen fought against slavery and debtor prisons. He was a trustee of a legacy estate for establishing libraries in the American colonies. He was also a trustee for the foundation of the colony of Georgia. He passed away at the age of 83.
Hidden heroes often have passions that extend outside their life’s work. For Stephen Hales, his work as a vicar of his parish was remarkable on its own, but his scientific discoveries span vast areas of science and influenced the work of other scientists for centuries. That a man who lived from 1677-1761 could be cited in a Nobel Prize speech in 1956 is a legacy of achievement that few have ever had.
* * *
“Reverend Stephen Hales Exemplary Priest, Eminent Scientist, Minister of this Parrish for 51 years.” (Memorial marker outside of Stephen Hales’ church)