galalith

from The Century Dictionary.

• noun A trade-name for a plastic material, a substitute for horn or celluloid, made by heating the casein of skim-milk, to which various coloring-materials are added, with acetate of lead or other metallic salts, and hardening by a solution of formaldehyde. Out of this material combs, handles for knives and forks, chessmen, buttons, and many other articles have been made.