Jan Ingenhousz or Ingen-Housz FRS (8 December 1730 – 7 September 1799) was a Dutch physiologist, biologist and chemist. He is best known for discovering photosynthesis by showing that light is essential to the process by which green plants absorb carbon dioxide and release oxygen. He also discovered that plants, like animals, have cellular respiration. In his lifetime he was best known for successfully inoculating the members of the Habsburg family in Vienna against smallpox in 1768 and subsequently being the private counsellor and personal physician to the Austrian Empress Maria Theresa.
Following his father's death in July 1764, Ingenhousz intended to travel through Europe for study, starting in England where he wanted to learn the latest techniques in inoculation against smallpox. Via the physician John Pringle, who had been a family friend since the 1740s, he quickly made many valuable contacts in London, and in due time became a master inoculator. In 1767, he inoculated 700 village people in a successful effort to combat an epidemic in Hertfordshire. In 1768, Empress Maria Theresa read a letter by Pringle on the success in the fight against smallpox in England, whereas in the Austrian empire the medical establishment vehemently opposed inoculations.
Thank you Jaga, in my ignorance or a gap in my education or memory I have to admid that I didn't knew this physician and scientist of Dutch descent. Ofcourse I have had the process of photosynthesis in my highschool without knowing that it was Jan Ingenhousz who discovered it.
Jan Ingenhousz, (born Dec. 8, 1730, Breda, Neth.—died Sept. 7, 1799, Bowood, Wiltshire, Eng.), Dutch-born British physician and scientist who is best known for his discovery of the process of photosynthesis, by which green plants in sunlight absorb carbon dioxide and release oxygen.
As a physician in London (1765–68), Ingenhousz was an early proponent of variolation, or the inoculation against smallpox through the use of live, unmodified virus taken from patients with mild cases of the disease. In 1768 he traveled to Vienna to inoculate the family of the Austrian empress Maria Theresa and subsequently served as court physician. Returning to London in 1779, he published the results of an ingenious study on the chemical effects of plant physiology, Experiments Upon Vegetables, Discovering Their Great Power of Purifying the Common Air in Sunshine, and of Injuring It in the Shade and at Night. The English chemist Joseph Priestley had already shown that plants restore to the air a property necessary to—but destroyed by—animal life. Ingenhousz found that (1) light is necessary for this restoration (photosynthesis); (2) only the green parts of the plant actually perform photosynthesis; and (3) all living parts of the plant “damage” the air (respire), but the extent of air restoration by a green plant far exceeds its damaging effect.
A man of varied scientific interests, Ingenhousz also invented an improved apparatus for generating large amounts of static electricity (1766) and made the first quantitative measurements of heat conduction in metal rods (1789).
Jaga, in my ignorance or a gap in my education or memory I have to admid that I didn't knew this physician and scientist of Dutch descent. Ofcourse I have had the process of photosynthesis in my highschool without knowing that it was Jan Ingenhousz who discovered it.