On the physical properties of gold leaf at high temperature

Abstract

Abstract In a paper by Prof. T. Turner * some experiments were described which show that gold leaf becomes transparent when heated in contact wild glass. The following experiments, suggested by Prof. H. A. Wilson, were undertaken to see if this effect takes place when the gold leaf is heated by itself. Hie apparatus in which the leak was heated consisted of a double walled fused quartz crucible. The outside of the crucible was 6 cm. deep and 5 cm. wide, and the inner chamber was 4·5 cm. deep and 3·5 cm. wide. Both chambers were fitted with lids. Inside the inner chamber, as near to the leaf as possible, a thermocouple, composed of platinum and nickel wires, was placed. The other ends of the couple dipped into mercury cups immersed in melting ice, from which wires led through a reversing key to a dead-beat galvanometer, with lamp and seals, a resistance of 800 ohms being included in the circuit.