Nitrocellulose was used to make the first flexible and transparent film. The process was developed by the Reverend Hannibal Goodwin in 1887, and introduced by the Eastman Dry Plate and Film Company in 1889. The film's ease of use combined with intense marketing by Eastman-Kodak made photography increasingly accessible to amateurs.
Early nitrate can be identified by the lack of markings along the edge of the film. Nitrate film manufactured between 1913-1939 has "nitrate" embossed along the edge.
Nitrocellulose is highly flammable and tends to deteriorate over time.
Flames cannot be extinguished with water because the oxygen released by the burning nitrate feeds the fire -- AND burning nitrate produces carbon monoxide fumes which are noxious.
Because of this danger, there was once a handmade sign in the basement of the Library of Congress that said, "In case of fire run like hell...."