Jan Ingenhousz
Encyclopedia : J : JA : JAN : Jan Ingenhousz
Jan Ingenhousz or Ingen-Housz (December 8, 1730 - September 7, 1799) was a Dutch-born British physiologist, botanist and physicist. He is best remembered for showing that light is essential to plant respiration, the first step in the discovery of photosynthesis.
Ingenhousz discovered that, in the presence of light, plants give off bubbles from their green parts while, in the shade, the bubbles eventually stop. He identified the gas as oxygen (for this discovery he is known affectionately as "the Oxygen man"). He also discovered that, in the dark, plants give off carbon dioxide. He realised as well that the amount of oxygen given off in the light is more than the amount of carbon dioxide given off in the dark. This demonstrated that some of the mass of plants comes from the air, and not only the soil.
In 1785, he described the irregular movement of carbon dust on alcohol and therefore has a claim as discoverer of what came to be known as brownian motion.
External links
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.