Early 19th century
- 1801 - J W Ritter and W H Wollaston
discovered Ultraviolet, by its chemical effects.
- 1801 - Thomas Young presented the principle of
the interference of light.
In 1802, William Hyde Wollaston fitted the entrance of his spectroscope
with a fine slit to improve resolution and discovered the presence
of fixed black lines within the solar spectrum.
In 1814, Joseph von Fraunhofer invented
the diffraction grating (transmission). After fitting it onto a
theodolite, he resumed Wollaston's work and marked the relative
positions of several hundreds of black lines. He was, however, unable
to provide a satisfactory explanation for their presence.
- 1807 - Young presented the three colour theory of vision.
- 1811 - Arago discovered rotary polarization by quartz.
- 1813 - Arago discovered the polarization of scattered light.
- 1815 - Fresnel rediscovered the interference of light.
- 1818 - Fresnel explained the polarisation of light.
- 1826 - Balard discovered the photo-sensitivity of silver bromide.
- 1826 - Talbot and Herschel studied the changing colours of flames
when sodium, potassium, lithium and strontium salts were introduced
into the flame.
Authors: Jean Charles Lefebvre,
and Richard Payling, Surface Analytical
First published on the web: 15 December 1999.