1. A LIQUID METAL SWITCH ADAPTED SELECTIVELY TO CONNECT AN ELECTRIC LOAD IN SERIES IN AN ELECTRIC CIRCUIT AND TO SHUNT SAID LOAD, THE SWITCH COMPRISING (A) A PAIR OF ELECTRICALLY CONDUCTIVE CONTAINERS CONNECTED TOGETHER ELECTRICALLY AND ADAPTED FOR CONNECTION TO AN ELECTRIC CIRCUIT, (B) ELECTRICALLY CONDUCTIVE METAL CONTAINED IN ONE OF THE CONTAINERS IN A LIQUID STATE, (C) PASSAGEWAY MEANS COMMUNICATING THE PAIR OF CONTAINERS WITH EACH OTHER FOR TRANSFERRING THE LIQUID METAL SELECTIVELY THEREBETWEEN, AND (D) VALVE MEANS IN THE PASSAGEWAY MEANS FOR OPENING AND CLOSING THE LATTER, (E) ONE OF THE CONTAINERS BEING ADAPTED TO RECEIVE THEREIN AN ELECTRICAL CONDUCTOR CONNECTING AN ELECTRIC LOAD IN SERIES IN THE ELECTRIC CIRCUIT WHEN LIQUID METAL IS CONTAINED IN SAID ONE CONTAINER, (F) THE OTHER CONTAINER BEING ADAPTED TO RECEIVE THEREIN A SECOND ELECTRICAL CONDUCTOR SHUNTING THE ELECTRIC LOAD WHEN LIQUID METAL IS CONTAINED IN SAID OTHER CONTAINER.