Resistivity of Bismuth at the Temperature of Liquid Air. 73 



micrometer in twenty to thirty places, these diameters having very 

 nearly equal values, and a mean value of O05245 cm. The bismuth 

 wire so prepared was mounted on a suitable holder, and its resistance 

 was taken at several different temperatures and in liquid air, the 

 temperatures being in all cases measured by our standard platinum 

 thermometer iPj.* 



The results of these measurements were as follows : 



Resistivity of Electrolytic Bismuth, No. I. 



The carve of resistivity plotted from these data is shown in fig. 1, 

 and in the table the value of the resistivity of bismuth in C.Gr.S. 

 units per cubic centimetre is given above. These values of the 

 resistivity show that in the case of this pure electrolytic bismuth 



Fio. 1. 



f 00,000- 



-Zoo* 



-/?" o- 



Temperature in Platinum Degrees. 



+ loo ? 



* For details of this thermometer, see Dewar and Fleming on the " Thermo- 

 electric Powers of Metals and Alloys at the Boiling Point of Liquid Air," ' Phil. 

 Mag.,' July, 1895, p. 100. 



VOL. LX. G 



