On the Movements of Liquid Metals in the Voltaic Circuit. 151 



with a solution of caustic potash, also with a plate of tin. 3rd. 

 A portion of Newton's fusible alloy was melted under a layer -J-th of 

 an inch deep of a solution of chloride of zinc, and the ends of the 

 platinum wires from the battery immersed in the supernatant liquid 

 until the alloy cooled and solidified ; the zinc solution flowed from 

 the negative towards the positive wire as long as the surface of the 

 alloy remained in the liquid state, and ceased to flow immediately the 

 surface of the metal solidified. Also a drop of a strong solution of 

 caustic potash placed upon the melted fusible alloy, the latter con- 

 nected with the negative pole and the former with the positive pole, 

 exhibited the usual momentary repulsions as long as the surface of 

 the alloy remained fluid. I therefore conclude that both the substances 

 must he in a liquid state. 



8. To ascertain whether both the substances must be conductors 

 of electricity : — 1 st. I formed melted globules of phosphorus in warm 

 oil of vitriol, also in a hot mixture of one measure of distilled water 

 and two measures of oil of vitriol, and immersed the wires in the usual 

 manner, but no motion of the liquid occurred. 2nd. No movements 

 were obtained with a globule of bromine under warm oil of vitriol ; a 

 large globule of bromine was placed in a porcelain boat, and dilute sul- 

 phuric acid added until the bromine was partly covered ; the wires 

 were then applied, but no movements took place. Also the addition 

 of sulphur and of selenium to the bromine did not ensure a different 

 effect. 3rd. With a large globule of selenium under fused chloride 

 of zinc no motion was obtained. 4th. I made similar experiments 

 with globules of chloroform, also of bisulphide of carbon in dilute sul- 

 phuric acid, but obtained no movements. 5th. No movements took 

 place with globules of chloroform in a solution of caustic potash or of 

 sulphate of alumina. 



9. To determine whether one of the substances must be metallic : — 

 1st. A definite layer of oil of vitriol was placed beneath a layer of 

 distilled water weakly acidulated with sulphuric acid, and the terminal 

 wires immersed in the upper liquid ; no movements occurred at the 

 boundary line of the two liquids. 2nd. A dense solution of cyanide 

 of potassium was placed in a small glass beaker, a few particles of 

 charcoal were sifted upon its surface, and a layer of aqueous ammonia 

 \ an inch deep carefully poured upon it. A vertical diaphragm of 

 thin sheet gutta percha was then fixed so as completely to divide the 

 upper liquid into two equal parts ; the vessel was placed in a strong 

 light, and two horizontal platinum wire electrodes from 66 pairs of 

 freshly -charged Smee's batteries immersed -J-th of an inch deep in the 

 liquid ammonia on each side of the diaphragm. A copious current of 

 electricity circulated, but no movements of the liquids at their mutual 

 boundary line could be detected. A small globule of mercury placed 

 in the lower liquid at once produced evident signs of motion. One 

 of the substances must therefore be a metallic conductor of electricity. 



10. To ascertain whether the capability of producing these move- 

 ments was a general property of metals and alloys when in the liquid 

 state : — 1st. Bismuth was fused beneath a layer of chloride of zinc ; 

 tin was also melted under a similar layer, and the terminal wires im- 



