679 



This table gives in general the same as fig. 6 and 7 of § 8. 

 The disappearance of the resistance extends over a much larger 

 field of temperature than with the mercury thread, probably because 

 the giving off of heat is considerably reduced by the winding up 

 of the wire protected by picëin ; which is probably also the reason 

 why at the lowest temperature the strength of the current cannot 

 be raised above 0.8 amp. and the threshold value of the current 

 density therefore only reaches 56 amp/In^u^ 



