Item no. P1863 (cover)

Type: cover

Country: USA

Date of use: 5 May 1942

Business cover used by the company Chemical Works MALLINCKRODT in New York, a chemical factory (operating since 1867) producing various products, also chemicals for photographic purposes that were described in “Mallinckrodt Photographic Chemicals” (e.g. issue 1943). It was for some time (since 1880) a major producer of bromides for photography. Mallinckrodt published manual (several times reissued) “The Chemistry of Photography” (1931). The cover bears US military censorship marks used during World War II.