Photosynthesis is a subject that most people begin to learn during the early years of their education and then study the topic in much greater detail at a high school. It is such a well-known process that few people think about how photosynthesis was first discovered and who the scientist was who realized that it existed. The man who first made this realization was Jan Ingenhousz and this was not his only scientific breakthrough or discovery.
Igenhousz was born on December 8, 1730, into the patrician Ingen Housz family. He first began to study medicine at the age of just 16 at the University of Leuven. After obtaining his MD, he went on to study for a further two years at the University of Leiden. Electricity became a topic of interest to him during this time. After completing his studies, he returned to his hometown, Breda, to begin a general medical practice.
1764 was the year his father died and Igenhousz decided to travel around Europe studying. His first destination was England and it was there he began to learn about inoculations against smallpox, which was a big problem at that time, from John Pringle. After three years, he had gained enough experience in this field to combat an outbreak of smallpox in Hertfordshire when he successfully inoculated 700 village people.
At that time, Maria Theresa was an Austrian Empress and she had read a letter about the success with the English smallpox inoculation program. The Austrian government was against any such inoculation programs but Maria Theresa wanted her own family inoculated against the disease. She took advice from the British experts and Jan Ingenhousz was selected for the job, so he traveled to Austria.
His main aim was to inoculate Maria Theresa’s family and he planned to do this by pricking the pus of a smallpox sufferer with a needle and then pricking the members of the Royal Family with the same needle. His idea was that by introducing a few of the germs to their bodies, their immune systems would develop an immunization against the disease. As this was successful, he was appointed as the court physician for Maria Theresa. By 1775, he had married Agatha Maria Jacquin and the couple chose Vienna as their home.
It wasn’t until the 1770s that the biologist first became drawn to the science of plants. He had met the scientist Joseph Priestley at a house party at Birstall, West Yorkshire. It was Priestley that had discovered that plants can make and absorb gases. Priestly’s findings led to Ingenhousz then also developing a keen interest for this topic and began to study the gaseous exchanges of plants.
It was 1779 when he made his first major discovery as he realized that plants gave off bubbles from their green parts when they were kept in the light. The bubbles would eventually stop if the plants were kept away from the light.
Around the same time, the biologist discovered that plants gave off carbon dioxide. He was able to calculate that the amount of oxygen released by a plant when it was positioned in the light is greater than the amount of carbon dioxide released away from the light. From these findings, he summarized that part of a plant’s mass comes from the air and not just the nutrients and water from the soil. This process became known as photosynthesis.
Although it is for his studies into photosynthesis for which he is most famous, this was not his only scientific work. Throughout his career, he traveled around many parts of Europe, including France, Scotland, and Switzerland. He often worked closely with both Henry Cavendish and Benjamin Franklin. During 1769, his work was formally recognized when he was officially elected to become one of the Fellows of the Royal Society of London. He then discovered that coal dust moved irregularly on top of alcohol and this later became known as the Brownian movement,
Sadly, in 1799, Jan Ingenhousz passed away at his home in Calne, England. He was laid to rest at the cemetery at Calne’s St. Mary the Virgin Church. The following year, his wife also died. Although it is now almost 219 years since his death, his memory lives on because of his scientific discoveries. It is only because of this magnificent scientist that people now have a full understanding of how plants grow and the contribution they make to the environments. This little-known biologist is often not appreciated enough for the contribution he made to science.