Timeline of chemistry

This timeline of chemistry lists important works, discoveries, ideas, inventions, and experiments that significantly changed humanity's understanding of the modern science known as chemistry, defined as the scientific study of the composition of matter and of its interactions.

Known as "the central science", the study of chemistry is strongly influenced by, and exerts a strong influence on, many other scientific and technological fields. Many historical developments that are considered to have had a significant impact upon our modern understanding of chemistry are also considered to have been key discoveries in such fields as physics, biology, astronomy, geology, and materials science.

Prior to the acceptance of the scientific method and its application to the field of chemistry, it is somewhat controversial to consider many of the people listed below as "chemists" in the modern sense of the word. However, the ideas of certain great thinkers, either for their prescience, or for their wide and long-term acceptance, bear listing here.

Empedocles asserts that all things are composed of four primal roots (later to be renamed stoicheia or elements): earth, air, fire, and water, whereby two active and opposing cosmic forces, love and strife, act upon these elements, combining and separating them into infinitely varied forms.

Leucippus and Democritus propose the idea of the atom, an indivisible particle that all matter is made of. This idea is largely rejected by natural philosophers in favor of the Aristotelian view (see below).

Plato coins term ‘elements’ (stoicheia) and in his dialogue Timaeus, which includes a discussion of the composition of inorganic and organic bodies and is a rudimentary treatise on chemistry, assumes that the minute particle of each element had a special geometric shape: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth).

Aristotle, expanding on Empedocles, proposes idea of a substance as a combination of matter and form. Describes theory of the Five Elements, fire, water, earth, air, and aether. This theory is largely accepted throughout the western world for over 1000 years.

Lucretius publishes De Rerum Natura, a poetic description of the ideas of atomism.