ConductiviUi of a Solution of Copper Sidpli.ate. 137 



T is the temperature centi<^ia(]e, R the observed resistance of 

 the system in legal ohms, aiul /.• is the conductivit}', i.e., the 

 rrciproeal of the specific resistance. Taking « as the specific 

 resistance r = ^^. where r is the mean radius, and I is the 

 length increased by "8 /■ at each end, ^72 i« a constant for 

 tile instrument determined by measurement once for all. 

 Thus k = 



logl 



loo- R = l-2:)4() 



j, and log 



log R^ so tliat the calculation of /• from the observed resist- 

 ances is veiy simple. The following tables show all the 

 observations used from whicli I calculated my results : — 



5-98 



R 



