Mid 19th century
In 1832, J F Herschel described the specific coloration
given to flames by metal salts. This was the first spectrochemistry
observation, from which major work on emission spectra originated.
It was fast found that emission spectra include bright lines at
- 1835 - Schwerd developed a "wave" theory of the diffraction
- 1837 - Knox discovered that the conductivity of selenium changes
- 1840 - Joseph Max Petzval (1807-1891) made the first portrait
- 1842 - Doppler discovered the effect named after him, that the
wavelength of light changes with the speed of the source relative
to the observer.
- 1845 - Michael Faraday (1791-1867) observed that a magnetic
field could rotate the plane of polarization of light.
- 1850 - Foucault showed that light travels more slowly in water
than in air, as predicted by wave theory.
M A Masson introduced in 1851 the apparatus shown above.
This is the first spark emission spectrometer known. The set-up
consists of a prism mounted on a Duboscq goniometer with a rather
complete sparking source. Underneath the set-up are records of the
position of iron and copper emission lines in the visible domain.
- 1856 - Ludwig Philipp van Seidel (1821-1896) derived the theory
of third order aberration.
Authors: Jean Charles Lefebvre,
and Richard Payling, Surface Analytical
First published on the web: 15 December 1999.