A: Duboscq type colorimeter, biological, with electric illuminator. Hollow black cast iron base attached to a sloping cast iron upright supporting the reader, prisms, and sample cups; reader detaches with two metal…

Cast iron base attached to a sloping cast iron upright supporting the reader, prisms, sample cups, and a mechanism for raising and lowering the sample cups on a focusing rail; metal knobs on each side control the height…

Azurite is a copper carbonate hydroxide mineral renowned for its striking deep blue color and historical use in pigment production. It is produced by weathering of copper ore deposits, and its chemical formula is…

Sample book with dyeing instructions and an 18-section foldout containing 143 dyed feathers.

A red display box of 24 samples of various products colored with dyes. The top and side flaps open to reveal 24 samples of various products colored with dyes. Includes liquids in small bottles, powders in brass circular…

Round glass bottle with glass stopper; label attached to front identifies manufacturer and contents (label has been waxed over).

Round glass bottle with cork stopper; label attached to front identifies manufacturer and contents (label has been waxed over).