Plato compared it to a wax tablet. Freud likened it to a “mystic writing pad” (made out of wax paper and celluloid). To remember could be akin to minting a coin (according to Hugo of St Victor) or entering a storage space (Augustine). From the archive

The metaphors of memory

Machines in the mind

ECON.ST

Test Tube Burger To be Unveiled in October

The $330,000 project would mark an important step in effort to develop synthetic meat.

Celluloid is the name of a class of compounds created from nitrocellulose and camphor, plus dyes and other agents. Generally regarded to be the first thermoplastic, it was first created as Parkesine in 1862^[1] and as Xylonite in 1869, before being registered as Celluloid in 1870. Celluloid is easily molded and shaped, and it was first widely used as an ivory replacement. Celluloid is highly flammable and also easily decomposes, and is no longer widely used. Its most common uses today are in table tennis balls and guitar picks.

celluloid

(sĕl'yə-loid')

^[2]

n.
A colorless flammable material made from nitrocellulose and camphor and used to make photographic film.

Motion-picture film: "a strange, anachronistic sight: theater pieces transferred to celluloid" (David Ansen).
The cinema; motion pictures: "There are no heroes but in celluloid" (Charles Langbridge Morgan).

adj.
Made of or using a material made from nitrocellulose and camphor.
Of or portrayed on film or in motion pictures.
Artificial; synthetic 合成的 : a novel with flat, celluloid characters.

[Originally a trademark.]