It was later found that this electrical conductance could be observed across a non-conductive layer of glass microspheres, where the only possible conductive structures were filamentous bacteria belonging to the family Desulfobulbaceae.
Det blev senere opdaget, at denne elektriske konduktans kunne blive observeret over et ikke-ledende lag af mikroglaskugler, hvor den eneste mulige ledende struktur var filamentøse bakterier, som tilhører til familien Desulfobulbaceae.