Historical Background - Classical (1750-1820 AD)
1752  AD  Benjamin Franklin shows that lightning is electricity.
Joseph Black conducts a series of experiments on alkaline and alkaline-earth carbonates, bringing pneumatic chemistry back into vogue.
1754 Joseph Black discovers "fixed air" (carbon dioxide).
1761 Joseph Black discovers that ice absorbs heat without changing temperature when melting 
1766 Henry Cavendish isolates hydrogen and defines it as pure phlogiston.
1771 Priestly discovers that plants convert carbon dioxide into oxygen.
1772 Antoine Lavoisier experiments on combustion.
Nitrogen isolated by Daniel Rutherford and Henry Cavendish.
1774 Priestley discovers oxygen (dephlogisticated air), and visits Lavoisier in Paris (discovered independently by Scheele in 1775). 
1778 Carl Scheele and Lavoisier discover that air is composed mostly of nitrogen and oxygen.
1780 Lavoisier and Pierre Laplace publish a memoir on heat, which concludes that respiration is a form of combustion.
1781 Lavoisier states law of conservation of mass.
Priestley creates water by igniting hydrogen and oxygen.
Kant publishes The Critique of Pure Reason, which asserts the impossibility of knowledge regarding the existence of atoms.
1783  Lavoisier proposes new chemistry, based on the notion of a chemical element.
1786 Kant declares that chemistry cannot be a science in the proper sense of the term.
1787 Méthode de Nomenclature Chimique published by Lavoisier, Guyton, Berthollet, and Fourcoy.
1789 Lavoisier publishes Traité Élémentaire de chimie.
1797 Joseph Louis Proust formulates law of definite proportions.
1798 Count Rumford proposes the idea that heat is a form of energy.
1799 Alessandro Volta invents electric battery (announced in 1800).
The Royal Institution is founded in London.
1800 William Nicholson discovers electrolysis.
Nicholson and Anthony Carlisle use electrolysis to separate water into hydrogen and oxygen.
Herschel discovers infrared radiation.
1801 Johann Wilhelm Ritter discovers ultraviolet radiation.
John Dalton formulates the law of partial pressures.
Founding of the Royal Institute (Great Britain).
1802 Dalton compiles his first table of atomic weights (published in 1805).
Joseph Louis Gay-Lussac formulates the law of combining gases in terms of rational and simple relations of volume.
1803 Dalton advances atomic theory, contending that matter is composed of matter of different weights.
Dalton states law of multiple proportions.
1806 Davy’s first Bakerian lecture, “On Some Chemical Agencies of Electricity.”
1807 Davy discovers potassium.
1808 Dalton’s atomic theory of chemical combinations laid out in A New System of Chemical Philosophy.
Davy develops the first electric powered lamp.
1810 Davy shows that chlorine is an element.
1811 Amedeo Avogadro claims that equal volumes of gases should contain equal numbers of molecules.
Gay-Lussac and Louis-Jacques Thenard show that hydrocyanic acid does not contain oxygen, refuting Lavoisier’s contention that oxygen is characteristic of acids.
1815 William Prout claims that hydrogen is an atom and that all other atoms are built up from different numbers of the hydrogen atom (Prout’s hypothesis).
1816 Augustin Jean Fresnel demonstrates the wave nature of light.
1817 Fresnel and Young show that light waves consist of transverse vibrations.
1818 Jons Jacob Berzelius publishes his table of atomic weights.