Thon wo take a piece of wire a_nd bend ifc bo a right angle aboub an inch from tho ond, puss it bhrough bhe cork or bung of a clean dry pickle-bobble, and having cut two pieces of gold loaf, about half an inch wide by an inch and a half long, wo can atbach them ono to each side of tho bent pieco of the wire, by putting a vory little gum on tho latter and carefully picking up the then metal thereby. The cord may bhen be placed carefully in the pickle-bobble, wifch bhe leaves banging down sido by sido in the middle. A less delicate instrument/ may be made by using two piecesof cigarette paper instead of fche metal—but fche latter is better. Now, if we apply a piece of.rubbed glass bo bhe top of the wire, outside tho bobble, tho gold leaves will fly apart, because, both boing influenced by fcho same elec tricity, they repel each other. Bub as soon as we touch the wire with a finger, the leaves fall by their own weight. The glass must not have been rubbed wifch too much energy, or the leaves will be broken by the force of their mutual repul sion. Now for the experiment of conduction — though we have had conduction already, because the electricity travels down the wire put; bhrough fche cork of this little in strument, which is properly called an elec troscope. Let us attach one end of a long piece of wire to a glass rod, and fche other end of the same wire fco the electroscope. The wire can be made to sfcay on the glas3 rod by coiling it round. If we now nub the •rod with a piece of silk or leather, the olec fcricifcy called into being will travql along the wire, and cause the gold leaves in the electroscope fco immediately diverge, aa before. If is prevented from escaping (as electricity- always ' trios' to do) by the pickle bottle boing made of glass,. Glass is one of the substances called ' infiuLafcors' ; india-rubber, sealing wax, vulcanite, oil and air are others. A more striking experiment is made with what is called fcho Leyden jar, which is easily made by anyone. 