James Prescott Joule (1818)

James Prescott Joule was born in 1818 in Salford, England. He was tutored at home and was expected to go into the family brewery business, along with his brother, Benjamin. When James was 16 years old, both boys were sent to learn chemistry from John Dalton, the "father of modern chemistry." Although James had responsibilities with the brewery, he began a lifetime of scientific experimentation.

James Joule's experiments with chemical properties, heat, and electricity led to the field of science called "thermo-dynamics." Joule published 97 scientific papers, and shared more than 20 with other scientists. Joule determined that heat is a form of energy and that energy can be changed from one form to another. He shares credit for discovering the law of the conservation of energy, which says that energy used in one form will reappear in another" and will never be lost. In 1840, he declared another law of science that says that heat is produced in an electrical conductor and is now called Joule's Law. The international unit of energy, the joule, is named in his honor.

Last Revised: April 2010
Sources: Electrical Engineer (London) (October 18, 1889), pages 311 – 312, obituary of Dr. Joule printed on Google books.