Resistance of Metals and Alloys. 



295 



-Rt. 



t°. 



pt. 



pt. 



2-2252 



196-1 



37640 



1930 



1-9384 



142-7 



32788 



141-4 



1-6536 



90-35 



27971 



90-55 



1-4650 



53-00 



24781 



53-60 



1-2982 



18-65 



21959 



1905 



1-2659 



1265 



21413 



12-95 



1-2080 



10 



20433 



10 



0-9972 





16868 



- 44-6 



0-8310 





14056 



- 81-9 



03564 





6029 



-197-1 



Volume-specific resistance at 0° 0. =20380 C.G.S. units. 

 Mean temperature-coefficient between 



0°C. and 100° C =-00411. 



§ 20. XIV. Thallium. 



Prof. Ramsay was so good as to prepare for us some pure 

 thallium by reducing in a porcelain crucible with potassic 

 cyanide some pure re-crystafiized thallous iodide. The metal 

 was then pressed cold in a steel press into a wire and kept 

 under paraffin oil. 



Length=150 centim. Mean diameter =0*0669 70 centim. 



Mean sectional area = 0*0035225 sq. centim. 



Lo g 1 { 10 l 9 e ngth OD ] =4-3707588=log 10 *. 



Ef. 



t°. 



pt. 



pt. 



1-0863 



98-5 



24660 



98-5 



0-9694 



60-0 



22006 



60-55 



0-8259 



17-2 



18749 



17-55 



0-7798 



0-7 



17702 



0-7 



0-6146 





14433 



- 44-9 



0-5037 





11829 



- 81-9 



0-2081 





4888 



-197-1 



Volume-specific resistance at 0° C. =17633. 



Mean temperature-coefficient between 



0° C. and 100° =-00398. 



§ 21. The resistance-curves of all the above metals are 

 delineated on the chart (see Plate II.) to a suitable 

 scale. An examination of these lines will show that some of 

 them are concave upwards and some concave downwards; 

 those with the most marked curvature being the magnetic 

 metals nickel and iron. The lines cross one another at low 

 temperatures, and hence the order of conductivity of the 



