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solution of sulphate of potash, the sudden repulsions were produced 

 readily, but were much less powerful than when the liquid was placed 

 alone upon the mercury. 2nd. Two circular clean spaces, \ an inch 

 wide, were scraped with a knife upon a horizontal plate of zinc ; one 

 of them was amalgamated with mercury and left covered with a very 

 shallow layer of that metal, the other was also amalgamated, but the 

 excess of mercury was wiped off ; each of the spots was now covered 

 with a shallow layer of a weak solution of sulphate of alumina, the 

 zinc plate connected with the negative plate of the battery, and the 

 end of the positive platinum wire dipped in succession into the super- 

 natant portions of liquid ; the solution above the thin layer of liquid 

 mercury was powerfully repelled on making the contact, whilst that 

 upon the other spot was unaffected. Similar results were obtained 

 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 be 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 vitriolj 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- 



