176 



DR CARGILL G. KNOTT ON THE 



Table showing the Values at different Temperatures of the "Logarithm Rate" (R~ 1 dR/dt) 



for Palladium and Hydrogenium. 



(For convenience of tabulating, the numbers are multiplied by 10 4 .) 



Temperature. 



Palladium. 



I. 



II. 



III. 



IV. 



V. 



VI. 



23° C. 



34 



36 



35 



27 



28 



20 



21 



33° 



33 



33 



31 



28 



25 



23 



20 



43° 



32 



33 



30 



25 



24 



22 



21 



53° 



30 



33 



28 



28 





22 



21 



63° 



29 



32 



29 



28 





22 



19 



73° 



30 



31 



28 



25 





21 



21 



83° 



27 



30 



29 



27 





22 



20 



93° 



25 



27 





25 





22 



19 



103° 



25 







26 





19 



18 



113° 















18 



If means are taken for the first three numbers in all the columns, and then 

 means of the next four, a condensed table will be obtained, which may be 

 regarded as giving fairly approximate values for the logarithm rates at tempera- 

 tures 33° and 68° These are as follows : — 





Mean Values of t= — — at 

 R dt 



33° 



68° 



Palladium, . . 



Hydrogenium I. 



II. 



III. 



IV. 



V. 



VI. 



33 

 34 

 32 

 27 

 26 

 22 

 21 



29 

 32 



28 

 27 



22 



20 



These numbers bring out very clearly the fact that the first effect of adding 

 hydrogen to palladium is to make the resistance of the wire somewhat more 

 sensitive to changes of temperature, but that this greater sensitiveness soon 

 disappears as more and more hydrogen is added. In the saturated condition, 

 hydrogenium resembles other alloys in having a temperature-coefficient for 

 change of resistance which is less than for pure metals. 



This conclusion regarding the first effect of adding hydrogen is borne out by 

 the results of the earlier series of experiments, which, though not having the 

 same claims to accuracy, are now given for purposes of comparison. In the 

 columns headed R//R are tabulated the ratios of the hydrogenium wire 

 resistances to the resistance of the wire in its pure palladium condition ; and in 

 the columns headed a'ja are tabulated the ratios of the corresponding tempera- 

 ture coefficients as given by the formula 



R' fl = R'(l+a0), 



