Metals fyc. in Fused Substances. 447 



of the ends of the electrodes out of the fused substance, which 

 in many cases could not be removed a sufficient distance to be 

 out of the influence of the heat ; 3rd, the chemical influence of 

 infusible or insoluble films formed upon the immersed electrodes; 

 4th, the accumulation of liquid of different composition around 

 the electrodes ; 5th, evolution of gases at the electrodes ; 6th, 

 alteration of structure of the electrodes by heat, their semi- 

 fusion, &c. ; 7th, currents occurring when by the relative cold- 

 ness of the electrodes the fused salt around them solidified ; and 

 8th, in addition to all these, the interference of impurities in the 

 fused substances and in the electrodes themselves. 



It will at once be seen that some of these interferences could 

 not be prevented or avoided ; with regard to the others, every 

 reasonable precaution was taken, and the results in each uncer- 

 tain case were properly verified. 



In the following lists the most positive substance is in each 

 case named first, and substances united by the mark — were 

 about equally positive. 



With fused Boracic Acid the following order of electrical rela- 

 tions was found. Iron, silicium — carbon, platinum, gold, copper, 

 silver. The currents obtained were very feeble. 



Glacial Phosphoric Acid. — Zinc, iron, copper, silver, platinum. 

 The copper, iron, and zinc dissolved quickly ; some of the gas 

 evolved by the zinc exploded. 



Large crystals of Iodine which had long been exposed in a 

 bottle near lumps of fused chloride of calcium gave, when fused, 

 feeble currents with silver and platinum, the former being 

 positive. 



Fused Selenium yielded no currents with platinum and copper 

 or silver. 



Sulphate of Ammonia. — Zinc, copper, silver, iron, platinum, 

 carbon. Copper evolved much gas and dissolved violently. 



Nitrate of Ammonia. — Magnesium, zinc, lead, copper, silver, 

 tin, aluminium, iron, silicium — carbon, platinum. Lead was very 

 strongly positive to copper without manifesting strong chemical 

 action, zinc evolved gas violently. 



Hydrate of Potash. — Silicium, aluminium, zinc, iron, lead (?), 

 carbon, copper, platinum, silver. Silicium was strongly positive 

 to aluminium, and strongly acted upon, with evolution of gas. 

 The results were variable with copper and platinum, and with 

 platinum and silver. 



Borate of Potash. — Iron, zinc, copper, silver, platinum. 



Phosphate of Potash. — Zinc, iron, copper, silver, platinum. 



Sulphide of Potassium. — Aluminium, zinc, copper, silver, pla- 

 tinum, carbon, iron. Copper and silver dissolved rapidly with 

 violent action. Reversals of current occurred with platinum and 



