letter scale
on pedestal made of
BOIS DURCI

The base of the letter scale is special. It is Bois Durci, that is translated: hardened wood. Bois Durci is made from finely ground sawdust, i.e. from wood powder or wood flour, mixed with albumin as a binding agent. Albumin is a protein from blood plasma. That blood came from cattle from slaughterhouses in Paris. The mixture was heated in steel molds and compressed under high pressure. Then cooled quickly. The product thus made has a high density and is resistant to boiling water. Several types of wood are mentioned, for example ebony and rosewood. Some sources report the addition of dyes. As an alternative to albumin from blood, egg and gelatin are mentioned. On October 3, 1855, Charles-François Le Page, together with Talrich and Pi, obtained a patent for fifteen years with number 13898, entitled Fabrication de tous articles et objets en bois durci (Translated: Manufacture of all articles and items of hard wood). They were unable to set up series production of sufficient quality. They sold the patent to Alfred Latry in 1859, who was more successful. After 1870, the end of the original patent, more companies made Bois Durci products. Until 1926, when a fire destroyed the factory of the last producer André Hunebelle.
Bois Durci products include ink sets, pen trays, decorative frames, medallions, plaques, ornaments, barometers, thermometers. There are collectors of Bois Durci products. Bois Durci is sometimes called a bioplastic.
The model of this letter scale has been shown before, see here and also here. These letter scales are also from unknown maker(s). The letter scale shown here is probably made of nickel-plated copper. The total height is 19 centimeters, the diameter of the dial is 8 centimeters, the diameter of the letter plateau is 6.2 centimeters. The foot of Bois Durci is 4 centimeters high,