LogFAQs > #963836166

Films may go missing for a number of reasons. One major contributing factor is the common use of nitrate film until the early 1950s. This type of film is highly flammable, and there have been several devastating fires, such as the Universal Pictures fire in 1924, the 1937 Fox vault fire and the 1965 MGM vault fire.[1]
Black-and-white film prints judged to be otherwise worthless were sometimes incinerated to salvage the meager scrap value of the silver image particles in their emulsions.[2] Films have disappeared when production companies went bankrupt.[2] Occasionally, a studio would remake a film and destroy the earlier version.[2] Silent films in particular were once seen as having no further commercial value and were simply junked to clear out expensive storage space.[3]

Martin Scorsese's Film Foundation claims that "half of all American films made before 1950 and over 90% of films made before 1929 are lost forever."[4] Deutsche Kinemathek estimates that 8090% of silent films are gone;[5] the film archive's own list contains over 3,500 lost films.
A study by the Library of Congress states that 75% of all silent films are now lost.[6] While others dispute whether the percentage is quite that high,[7] it is impractical to enumerate any but the more notable and those that can be sourced.
For example, roughly 200 out of over 500 Mlis' films and 350 out of over 1,000 of Alice Guy's films survive.