saccharimeter (polaristrobometer)
Datecirca 1872
Inventory NumberDW0854a
ClassificationPolarimeter
Subject
Maker
Hermann & Pfister
1866 - 1881
Cultural Region
Place of Origin
Dimensionssaccharimeter: 42 × 57.1 × 27.9 cm (16 9/16 × 22 1/2 × 11 in.)
box: 17 × 61.2 × 27.9 cm (6 11/16 × 24 1/8 × 11 in.)
box: 17 × 61.2 × 27.9 cm (6 11/16 × 24 1/8 × 11 in.)
Material
Accessoriespine box; instruction manual; glass tubes (2); open-ended tube; gas lamp (DW0854b)
DescriptionThis saccharimeter differs from those of Soleil, Duboscq, Laurent, etc. because, instead of comparing the color of two semi-circles, it depends upon the disappearance of black interference fringes on a light background.
At one end is a polariscope, consisting of a magnifying objective lens, a diaphragm with crossed hairs, two sheets of calcspar 3mm thick, cut at 45-degree angles to the optical axis and crossed at right angles to their principal surfaces, and a Nicol analyzing prism. On the other end of the saccharimeter is a Nicol polarizing prism. Between them there is a space for the nickel tubes containing the sugar solution. There is a telescope running parallel that magnifies the reading on the vernier scale (which measures the angle that the analyzer is rotated). The instrument was designed to be used with a sodium lamp giving off a homogeneous yellow light (see DW0854b). The instrument is stored in a box when not in use.
A complete description is found on the following website.
At one end is a polariscope, consisting of a magnifying objective lens, a diaphragm with crossed hairs, two sheets of calcspar 3mm thick, cut at 45-degree angles to the optical axis and crossed at right angles to their principal surfaces, and a Nicol analyzing prism. On the other end of the saccharimeter is a Nicol polarizing prism. Between them there is a space for the nickel tubes containing the sugar solution. There is a telescope running parallel that magnifies the reading on the vernier scale (which measures the angle that the analyzer is rotated). The instrument was designed to be used with a sodium lamp giving off a homogeneous yellow light (see DW0854b). The instrument is stored in a box when not in use.
A complete description is found on the following website.
Signedon diaphragm, script: No. 445 / Hermann & Pfister / Bern
FunctionThis instrument is a type of polarimeter invented by Wild in 1864. A saccharimeter is a polarimeter adapted for use with light source (sun or artificial, monochromatic or not), and it measures the optical activity of sugar solutions. The analyzer and polarizer (which are usually prisms) would be aligned such that no light passed through. Then the liquid substance was placed in between them, in a glass vial, and then put within the long tube seen on the picture. Light passing through the liquid creates fringes. The analyzer, close to the eyepiece, would be rotated until the fringes disappeared, and that angle would characterize the optical activity of the substance.
ProvenanceDavid Wheatland purchased from Alain Brieux, Paris, June 1, 1964 (lot 17/11).
Félix Marie Pellin
Date: circa 1930
Object number: 1996-1-0365b
Louis Jules Duboscq
Date: circa 1875
Object number: 1997-1-1477a
See also/See also
