While perhaps the most extensive such timeline to date, it is surely not complete. Sources for further information have been
1666: Isaac Newton (1642–1727) (Figure 1) shows that the white light from the sun could be dispersed into a continuous series of colors. He coined
the word "spectrum." His apparatus, an aperture to define a light beam, a lens, a prism, and a screen, was the first spectroscope.
He suggested that light was composed of minute corpuscles (particles) moving at high speed.
Figure 1: Sir Lsaac Newton.
1678: Dutch mathematician and physicist Christian Huygens (1629–1695) proposes the wave theory of light.
1729: French mathematician and scientist Pierre Bougeur (1698–1758) notes that the amount of light passing through a liquid sample decreases with increasing sample thickness.
1752: Thomas Melville (1726–1753) of the University of Glasgow, Scotland, observes a bright yellow light emitted from a flame produced by burning
a mixture of alcohol and sea salt. When the salt is removed, the yellow color disappears.
1760: German mathematician and scientist Johann Heinrich Lambert (1728–1777) publishes his "Law of Absorption."
1776: Italian physicist Alessandro Volta (1745–1827) (Figure 2) uses his "perpetual electrophorus" device for producing static electric charges to spark various materials.
He notes different colors with different materials. Eventually he is able to identify certain gases by the colors emitted
Figure 2: Alessandro Volta.
1786: American astronomer and instrument maker David Rittenhouse (1732–1796) produces the first primitive diffraction grating with parallel hairs laid across two screws.
1802: English scientist William Hyde Wollaston (1766–1828) is the first to observe dark lines in the spectrum of the sun.
1814: The German optician Joseph von Frauenhofer (1787–1826) invents the transmission diffraction grating and makes a detailed study of the dark lines in the solar spectrum.
1826: Scotsman William Henry Fox Talbot (1800–1877) observes that different salts produce colors when placed in a flame.
1851: M.A. Masson produces the first spark-emission spectroscope.
1852: German scientist August Beer (1825–1863) publishes a paper showing that the amount of light absorbed was proportional to the amount of solute in aqueous
1859: The German physicist Gustav Robert Kirchoff (1824–1887) and chemist Robert Wilhelm Eberhard von Bunsen (1811–1899) (Figure 3) discover that spectral lines are unique to each element.