You will investigate the process of photosynthesis by repeating the experiments of Joseph Priestley and Jan Ingenhousz.
After completing this tutorial, you will be able to complete the following:
Joseph Priestley (1733 - 1804) was born in England, traveled throughout Europe and in 1794 moved to America. He led an extraordinary life on both continents. While in Europe he met regularly with such notables as Erasmus Darwin, Antoine Lavoisier, James Watt, and Benjamin Franklin. While in America he opened the first Unitarian church, whose services were attended by soon to be President John Adams. Thomas Jefferson was also a correspondent of Joseph Priestley. Many people credit Joseph Priestley with the discovery of oxygen, although he referred to it as "dephlogisticated air." Priestley was also fortunate to, at one time, live near a brewery that gave him ready access to a supply of "fixed air" (carbon dioxide). He is most famous for his experiments in chemistry, but also performed experiments with electricity and published over 100 articles or books on subjects as far reaching as history, politics, theology, and education.
In Priestley's time gases were classified only by odor, color, and solubility. Priestley's work looked at the "goodness" of the gas. He saw that air was "injured" by breathing or combustion, and "restored" by the presence of plants. Priestley had to invent most of his own experimental apparatus, and as a result, it took him seven years to complete his work on air. Priestley often consulted with Lavoisier, which led Lavoisier to his new theories on oxygen's role in combustion and respiration.
Jan Ingenhousz (1730 -1799) is considered the "Father of Photosynthesis." His work added to Priestley's work by showing that light was necessary for plants to convert carbon dioxide into oxygen, and animals and plants both convert oxygen into carbon dioxide during respiration.
|Approximate Time||35 Minutes|
|Pre-requisite Concepts||Students should be familiar with photosynthesis, respiration, and Van Helmont.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||air, Antoine Lavoisier, bell jars|