all c.1880s, a Boyd's Battery, with patent dates for 1878, 1879, diameter 3.1cm; a Magneto Galvanic Battery child's size, American, patented in the U.S. February 3rd 1880, diameter 3.2cm; a Richardsons Magneto Galvanic Battery, American, 4.1cm across; a French 'MEDAILLE ELECTRO MEDICALE' by E. Osselin, octagonal with portrait bust, 3.9cm across; a medaille Electro Magnetique Carolus by Ferdinand de Boyere, 4.1cm (5)