John Dalton

Jeremias Richter and the Law of Definite Proportions

10. March 2023 Harald Sack

On March 10, 1762, German chemist Jeremias Benjamin Richter was born. He discovered the law of definite proportions and is best known for introducing the term stoichiometry, i.e. the calculation of relative quantities of reactants and products in chemical reactions. Youth and Education Jeremias Benjamin Richter was born at Hirschberg in Silesia, today’s Jelenia Góra in Western Poland. He graduated from the Hirschberg Gymnasium, and in 1778 joined the engineering corps of…

physics

James Prescott Joule and the True Nature of Heat

24. December 2021 Tabea Tietz

On December 24, 1818, English physicist and brewer, James Prescott Joule was born. Joule studied the nature of heat, and discovered its relationship to mechanical work. This led to the law of conservation of energy, which led to the development of the first law of thermodynamics. The SI derived unit of energy, the joule, is named after James Joule. “My object has been, first to discover correct principles and then to suggest their practical…

chemistry

Joseph Louis Gay-Lussac and his Work on Gases

6. December 2021 Tabea Tietz

On December 6, 1778, French chemist and physicist Joseph Louis Gay-Lussac was born. He is known mostly for two laws related to gases, and for his work on alcohol-water mixtures, which led to the degrees Gay-Lussac used to measure alcoholic beverages in many countries. “I have not chosen a career that will lead me to a great fortune, but not my principal ambition. In fact, later in life he enjoyed comfortable income…

chemistry

Joseph Proust and the Law of Constant Composition

26. September 2020 Harald Sack

On September 26, 1754, French chemist Joseph Louis Proust was born. He was best known for his discovery of the law of constant composition in 1799, stating that in chemical reactions matter is neither created nor destroyed. A Young Chemist Joseph L. Proust was born on September 26, 1754 in Angers, France as the second son of Joseph Proust, an apothecary, and Rosalie Sartre. Joseph studied chemistry in his father’s shop and later came to…

chemistry

John Dalton and the Origins of the Atomic Theory

6. September 2020 Harald Sack

On September 6, 1766, English chemist, meteorologist and physicist John Dalton was born. He is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness. He also recognised that the aurora borealis was an electrical phenomenon. “Philosophers are generally persuaded, that the sensations of heat and cold are occasioned by the presence or absence, in degree, of certain principle or quality denominated fire or…

chemistry

Jöns Jacob Berzelius – One of the Founders of Modern Chemistry

20. August 2020 Tabea Tietz

On August 20, 1779, Swedish chemist Jöns Jacob Berzelius was born. Berzelius is considered, along with Robert Boyle, John Dalton, and Antoine Lavoisier, to be one of the founders of modern chemistry. In Sweden, Berzelius Day is celebrated on 20 August in honor of him. “Every chemical combination is wholly and solely dependent on two opposing forces, positive and negative electricity, and every chemical compound must be composed of two parts combined by…

chemistry

Amedeo Avogadro – Relating Volumes to Quantities and Avogadro’s Law

9. August 2016 Harald Sack

On August 9, 1776, Italian scientist Lorenzo Romano Amedeo Carlo Avogadro, Conte di Quaregna e Cerreto was born. He is most noted for his contribution to molecular theory now known as Avogadro’s law, which states that equal volumes of gases under the same conditions of temperature and pressure will contain equal numbers of molecules. In tribute to him, the number of elementary entities (atoms, molecules, ions or other particles) in 1 mole…