Abstract: Apparatus for storing and dispensing pigmented marking particles into the development mechanism of a reproduction apparatus. The storing and dispensing apparatus comprises a cartridge including a housing for storing pigmented marking particles, and an elongated opening in the housing through which such marking particles may be dispensed. A cover is removably secured to the cartridge housing to seal the housing opening to prevent contamination of the environment by escape of such marking particles through the opening. The cover, in the preferred embodiment being a flexible sheet member, is selectively removed from sealing relation with the cartridge housing opening and held adjacent to the cartridge away from exposure to the environment when the cartridge is located relative to the development mechanism, whereby marking particles may readily be dispensed into the development mechanism through the housing opening and contamination of the environment is substantially prevented.

Abstract: An optically transmittant body comprising a solid solution of a ternary sulfide and a selected binary sulfide such as a solid solution of calcium lanthanum sulfide and phase lanthanum sulfide is provided by precipitating out of a nitrate solution of calcium and lanthanum, a starting powder of calcium carbonate and lanthanum carbonate. The molar ratio of lanthanum to calcium is greater than 2.0 moles lanthanum to 1.0 moles of calcium nitrate. The starting powder is reacted with a sulfurizing agent such as hydrogen sulfide to convert such starting powder into a powder of the solid solution of calcium lanthanum sulfide and phase lanthanum sulfide. The precipitate ion reaction forms a homogenous fine particle size starting powder of calcium carbonate and lanthanum carbonate which is substantially and uniformly converted into the solid solution powder. The phase lanthanum sulfide has a similar crystallographic structure as the calcium lanthanum sulfide.

Abstract: An optically transmittant body of a ternary sulfide material such as calcium lanthanum sulfide is provided by concurrently precipitating from a nitrate solution of calcium and lanthanum, calcium carbonate and lanthanum carbonate. The precipitation reaction forms a homogeneous fine particle size starting powder of calcium carbonate and lanthanum carbonate powders. The starting powder is reacted with a sulfurizing agent such as hydrogen sulfide to convert such starting powder into a calcium lanthanum sulfide powder. The particle size of the homogeneous starting powder is sufficiently small to permit substantially complete and uniform conversion of such starting powder into the calcium lanthanum sulfide powder. The calcium lanthanum sulfide powder is then compacted into the desired form of the optically transmittant body and is subsequently sintered at an elevated temperature in an atmosphere of excess sulfur to increase the density of the material.