46 



ELECTROLYSIS. 



RESISTANCE OF ANNEALED PURE COPPER WIRES AND BARS continued. 



CONDUCTIVITY OF COPPER ALLOYED WITH FOREIGN SUBSTANCES. 

 PURE COPPER = 100. (Matthiessen.) 



RELATIVE CONDUCTIVITY OF COPPER OF VARIOUS EXTRACTIONS. (Matthiessen.) 



Substances. 



1. Spanish, from Rio-Tinto, with 2 per 100 of arsenic, traces'! 



of lead, nickel, suboxide ) 



2. Russian, fiom Demidolf, with traces of arsenic, iron, nickel, 



suboxide 



3. Tough cake, extraction not mentioned, with traces of lead,| 



iron, nickel, antimony, suboxide J 



4. Best selected, extraction not mentioned, with traces of iron, j 



nickel, antimony, suboxide / 



5. Australian, from Burra-Burra, traces of iron and suboxide . . 



6. American, from Lake Superior, traces of iron, suboxide,} 



and 0-03 per 100 of silver / 



Conduc- 

 tivity. 



14-24 

 59-34 

 71-03 



81-35 

 88-86 

 92-57 



Tempera- 

 ture. 



14-8 

 12-7 

 17-3 



14-2 

 14-0 

 15-0 



