The present invention relates to a novel crystals of 5–propionyl-1–ethyl-amino}-methyl)-2-methoxy-benzoic acid and methods of making the zwitterion of 5–propionyl-1–ethyl-amino}-methyl)-2-methoxy-benzoic acid. A dielectric layer, an insulating layer, and a conductor layer are formed on a substrate in sequence. The housing has a shutter for selecting a subportion of the first revealed portion of the document by shutting off a portion of the viewing area, thereby hiding a portion of the first revealed portion of the document and revealing only the selected subportion. Further, outputs of the AND-NOR composite gates are fixed irrespective of a logical level of the enable signal E.