Experimental Researches in Electricity. 357 



tricity was directed through them, but on reaching the bar- 

 rier of ice, it was so effectually checked, that a galvanometer 

 introduced within the circuit, was not in the slightest degree 

 deflected. The moment, however, that liquefaction took 

 place, power of conduction followed, and this power was in- 

 variably accompanied by decomposition of the water. 



As it seemed very improbable that this law of the assump- 

 tion of conducting power during liquefaction and loss of it 

 during congelation would be peculiar to water, Faraday, 

 with characteristic earnestness and deep perception of the 

 relations of the law indicated, immediately experimented 

 on various other bodies of different chemical characters, and 

 obtained the most decisive evidence of its general applica- 

 bility, and of its right to be considered a true law of the 

 phenomena, the first requisite towards a philosophical in- 

 vestigation of the cause to which it was due. The various 

 substances experimented upon were, 



First. Water. 



Amongst Oxides. Potassa, protoxide of lead, glass of 

 antimony, protoxide of antimony, oxide of bismuth, chlorides 

 of potassium, sodium, barium, strontium, calcium, magnesium, 

 manganese, zinc, copper (proto) lead, tin, (proto) antimony, 

 silver. 



Iodides of potassium, zinCj and lead ; protoxide of tin ; per- 

 iodide of mercury ; fluoride of potassium ; cyanide of po- 

 tassium ; sulpho-cyanide of potassium. 



Salts. Chlorate of potassa ; nitrates of potassa, soda, 

 baryta, strontia, lead, copper, and silver ; sulphates of soda 

 and lead ; proto-sulphate of mercury ; phosphates of po- 

 tassa, soda, lead, copper, phosphoric glass, or acid phos- 

 phate of lime ; carbonates of potassa and soda, mingled and 

 separate : borax, borate of lead, per-borate of tin ; chromate 

 of potassa, bi-chromate of potassa, chromate of lead ; acetate 

 of potassa. 



Sulphurets. Sulphuret of antimony, sulphuret of po- 



