Signedon base: A. GAIFFE / FABRICANT d'INST'ts DE PRÉCISION, / 40 Rue St. André des Arts / PARIS
FunctionThis instrument is most likely an electric discharger, used for connecting a charged piece of apparatus (e.g., a Leyden jar) to a conductor, ground, or other piece of apparatus in order to discharge the former or transfer charge between objects.
It could, however, also have been used as a spark generator for medical purpose (Gaiffe was well-known for his electrotherapy instruments).