The insightful philosophers Leucippus and Democritus unveiled a hypothesis, a guess, about matter that has captivated thinkers for centuries. They postulated that:
1.The Indivisible: Everything is made of tiny, eternal particles called "atomos" — uncuttable.
2. The Void: These atoms move in a space, termed the "void."
3. Collisions and Alliances: Atoms encounter each other, sometimes combining or bouncing apart upon impact.
4. Diversity of Forms: Different substances are composed of atoms with varied sizes and shapes.
5. Qualitative Essence: Atoms’ unique arrangements and forms grant distinct sensory qualities to matter.
Centuries later, the Lavoisier partnership, through their pioneering experiment, provided evidence of these principles. "Lavoisier was a Parisian through and through and a child of the enlightenment," wrote biographer Henry Guerlac. Their Law of Conservation of Mass experiment presents empirical data mainly supporting ancient postulates 1 and 3: atoms are uncuttable, and they collide and bond without loss or gain in mass. By demonstrating that water is a compound formed from oxygen and hydrogen, not a singular element, they showed that atoms retain their identity through chemical reactions. The total mass remains constant, whether the atoms are free or combined, an enduring proof of the law and a brilliant affirmation of the atomic theory envisioned by the ancients. This revelatory work, highlighting Marie and Antoine Lavoisier's contributions, bridges the gap between ancient philosophical musings and empirical scientific evidence and continues to spark awe and inspiration in scientific exploration.
In June 1783, Lavoisier reacted oxygen with inflammable air, obtaining "water in a very pure state." He correctly concluded that water was not an element but a compound of oxygen and inflammable air, or hydrogen as it is now known. To support his claim, Lavoisier decomposed water into oxygen and inflammable air. Now, the composition of water was known. The experiment was published as Traité élémentaire de Chimie (Elements of Chemistry) in Paris in 1789.
