For 101 days beginning October 1768 Antoine Lavoisier (born Paris, 1743, died 1794) distilled and condensed water in a sealled container. Its weight remained unchanged. Water is inconvertable!
In 1771 at age 28, Antoine Lavoisier married 13 years old Marie-Anne Pierrette. She learned English to keep Antoine abreast of chemical progress occuring in England. She helped with the experiments, recorded observations and results, and drew sketches for his notebook and publications. They lived in an age when all accomplishments were attributed to men. But perhaps the
new chemistry of Lavoisier should be considered the product of their teamwork.
In 1772 he found, contrary to the Phlogiston theory, that burning both phosphorus and sulfur increases their weights, producing acid forming gases.
When Priestly visited Paris in October 1774, he met Lavoisier and shared his discovery of dephlogisticated air. Lavoisier amplified Priestly's experiment to prove that that air absorbed by heating mercury gently to form the red calx is exactly the same volume as the
dephlogisticated air liberated by heating more strongly.
Convinced that evidence was finally at hand showing that air and water are not single elements, Lavoisier believed that Boyle's century old proposed definition of element could explain all the distinctly different
airs as well as the weight contradictions in the phlogiston theory.
Elements are the substances we have not discovered means for separating. They are all the substances into which we are capable to reduce (in weight) bodies by decomposition. Lavoisier conducted a great systematic series of experiments, reporting the results periodically in
memoirs to the Academie Royale des Sciences.
All the while he was heavily engaged in official duties as fermier generale (financiers that leased the right for French tax collections on commerce). He also was active promoting improvements for French political, social, and economic conditions.Lavoisier published in 1789 the
Traite elementaire de Chimie...describing a revolutionary new system of chemistry. Lavoisier's book describes the new chemistry: besides the new concept of element, it contains
The Four Element Theory was abandoned: Each distinctive
Air becomes a different gas, many of them elements.
Water becomes a compound of the elements Hydrogene and Oxygene.
Earth is a variety of substances, mostly compounds.
Fire becomes two elements: Calorique (heat) and Lumiere (light).
The metal compounds studied by the alchemists become seventeen different elements. Mercury is merely one of the metallic elements. Mixtures of metals become alloys.
Combustion is the process of combination with Oxygene. All acids are compounds containing Oxygene and a distinctive element. Soufre (Sulfur) is one of six nonmetallic acidifiable elements. Salts are the combination of acids and either metals or earthly bases. Lavoisier expect the Alkalies to be found to be compound.
|Simple Subftances||Current Names:||non-metallic
Oxydable & Acidifiable
Oxydable & Acidifiable
|Simple Salifiable Earthy Subftances||Current Names:
element in chlorine+
element in fluorine+
element in borate
|* since rejected as elements||+ never isolated||(↑ decomposed later using electricity; now compounds, not elements)|
During the Reign of Terror in 1994, Antoine Lavoisier was arrested with 27 others by the French Revolutionary Tribune for abusing the office of fermier general by adulterating tobacco and water. They were guillotined the same day. Later Marie-Anne was briefly married to Count Rumford.
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|page created 23 March 2002
latest revision 26 April 2010
|by D Trapp|