Several films that would otherwise be entirely lost survive in the form of used for later films.
The Universal Pictures feature film The Cat Creeps (1930) is a lost film and its only remaining footage was included in a Universal short film called Boo! (1932). However, UCLA still has a copy of the soundtrack. The James Cagney film Winner Take All (1932) used scenes from the early talkie Queen of the Night Clubs (1929) starring Texas Guinan. While Queen of the Night Clubs was not a lost film in 1932, no prints of the film have survived through the decades, and only that footage included in Winner Take All remains.
Actress turned gossip columnist Hedda Hopper made her screen debut in a Fox Film called The Battle of Hearts (1916). The star of the film was William Farnum, then at the beginning of his long Fox contract. 26 years later in 1942 Hopper produced her short series Hedda Hopper's Hollywood #2. In the short, Hopper, Farnum, her son William Hopper, and William's wife Jane Gilbert view portions of Battle of Hearts. These brief portions of that movie survive within the Hopper documentary. More than likely Hopper had an entire print of the movie in 1942. However, like many early Fox films, Battle of Hearts is now lost or missing.
One of Charlie Chaplin's best-known works, the 1925 silent film The Gold Rush, was re-released in 1942 to include a musical track and narration by Chaplin himself. The reissue would end up having the unintentional result of preserving the film, as the original 1925 film (though generally not considered a lost film) shows noticeable degradation of image and missing frames, damage not in evidence in the 1942 version.
The Polish film
O czym się nie mówi from 1939 contains three short fragments of Arabella from 1917, one of Pola Negri's early films, which later became lost.