Stokes' apparatus for observing fluorescence
Date1850-1880
Inventory Number1997-1-1680
ClassificationPrism
Subject
Maker
Louis Jules Duboscq
French, 1817 - 1886
Cultural Region
Place of Origin
Dimensions40.9 x 17.8 x 13.2 cm (16 1/8 x 7 x 5 3/16 in.)
Material
Accessoriescardboard cover for prism (2)
Bibliography
DescriptionTwo small identical equilateral quartz prisms are mounted on this instrument, one on top of the telescoping brass stand, one on a short rotating arm. On a separate and longer rotating arm is a plano-convex quartz lens, framed in a black diaphragm. Two cardboard covers were made to protect the prisms.
The base is marked with an old Harvard inventory number: "10 29".
The base is marked with an old Harvard inventory number: "10 29".
In Collection(s)
Signedon prism's arm: J. DUBOSCQ / À PARIS
Curatorial RemarksThe prisms' cardboard covers may or may not be original to the instrument.
FunctionThis simple device works by allowing a ray of light to pass through the two prisms, where it becomes dispersed. It then passes through the lens, where it is concentrated at the focal point, creating concentric cones of colored light. By interposing a transparent liquid solution or substance in these colored rays one can ascertain which of them causes fluorescence.
George Gabriel Stokes (1819-1903), an Irish mathematician and physicist, discovered this phenomenon in the early 1850s. He found out that the wavelength of fluorescence emission is greater than that of the exciting radiation. Today, it is mainly used by ultra-violet radiation (black light), which is converted into a visible longer wavelength.
George Gabriel Stokes (1819-1903), an Irish mathematician and physicist, discovered this phenomenon in the early 1850s. He found out that the wavelength of fluorescence emission is greater than that of the exciting radiation. Today, it is mainly used by ultra-violet radiation (black light), which is converted into a visible longer wavelength.
Louis Jules Duboscq
Date: 1850-1880
Object number: 1997-1-1569
Louis Jules Duboscq
Date: circa 1875
Object number: 1997-1-1559
Louis Jules Duboscq
Date: circa 1875
Object number: 1997-1-1802
Louis Jules Duboscq
Date: 1850-1880
Object number: 1997-1-1571
Louis Jules Duboscq
Date: 1850-1875
Accessories: three prisms, smallest in cardboard box
Object number: 1998-1-0410
Louis Jules Duboscq
Date: 1850-1880
Accessories: spare mount for diaphragm
Object number: 1997-1-1553
Louis Jules Duboscq
Date: circa 1875
Object number: 1997-1-1477a
