saccharimeter

Date1870-1880

Inventory Number1997-1-0874b

ClassificationPolarimeter

Subject

Maker Louis Jules Duboscq French, 1817 - 1886

Cultural Region

Place of Origin

Dimensions3.2 × 24 × 3.2 cm (1 1/4 × 9 7/16 × 1 1/4 in.)

Material

DescriptionKnown as the Duboscq-Soleil saccharimeter, it would have been equipped at one end with a polarizer prism and a quartz wedge (optics at that end is missing). At the other end is an analyzer made of a Nicol prism, a compensator with vernier scale (that measures the richness of the liquid dissolution) made of quartz that moves sideways, and an eyepiece. Between the eyepiece and analyzer is a tint resetter made of a Nicol prism and a red piece of quartz. The empty space in the center is where a saccharimeter tube with a liquid solution would have been placed (see an example of such a tube in 1997-1-2029). The instrument was originally mounted on a stand.

The two accompanying objects, a saccharimeter tube and a telescoping brass tube do not appear to be original to this instrument. The saccharimeter tube, actually, do not fit the instrument.

For more information, see the following Duboscq trade catalogue here (in French).

Curatorial RemarksFor a complete example of a Duboscq saccharimeter, see 1993-1-0002.

FunctionA saccharimeter is a polarimeter adapted for use with a 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 one of the long tubes 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.