480 



Prof. Silas W. Holman on 



The Noll Data. — A contribution of much permanent value 

 to the data on thermo-electrics has recently been made by 

 Noll *, who has measured So e and t for thirty-two couples 

 oyer a range in most cases of 0° to 218° C. The metals em- 

 ployed (including carbon) were usually of a high and stated 

 degree of purity, and consisted of eighteen different sub- 

 stances, two of which were alloys (german silver and brass), 

 and the remainder samples of different degrees of purity or 

 hardness of the pure substances. The couples contained, as 

 one element, for the most part, either copper or mercury. 

 Temperatures were reduced to the air-thermometer scale. 



The Avenarius formula was applied to fourteen of the more 

 important of them by Noll. The deviations are given in 

 Table VIII. 



Table VIII. 

 NolPs Data on Pure Metals. 









/3- 



mv. 



Av. Pet. Deviation. 



Couple. 



m. 



n. 







Avenarius. 



Expon. 



Au-Hg 



4-6954. 10- 3 



2-136 



750-4 



+0-27 



+0-17 



Ag-Hg 



28637. 10~ 3 



2206 



677-8 



0-33 



0-15 



Ni-Cu 



8-2333. 10" l 



1-511 



3950-2 



0-30 



017 



(Od-Cu 



3-7617. 10 -11 



4-94 



40-7 



0-48 



3-40) 



Br-Ou 



2-4969. 10" l 



1-366 



531-1 



014 



013 



Zn-Hg 



8-2890 . 10 - ^ 



2-420 



651-6 



015 



0-18 



Pb-Cu 



1-7674 . 10, 



1-800 



4290 



005 



0-07 



C Ul -Hg 



4-6726 . 10" 3 



2-130 



768-4 



0-12 



011 



[Fe-Hg 



10913. 10 + * 

 8-3295.10 ~T 



0-7220 



6264-2] 







Oo-Hg 



2166 



1575-2 



0-26 



0-22 



Pt,-Cu 



2-1475. 10 -3 



2-266 



711-1 



008 



012 



Pt 2 -Cu 



H095.10" 3 



2-353 



5990 



0-19 



0-25 



Si^-Cu 



4-2021 . 10"* 



1-667 



482-8 



0-21 



09 



Mg-Cu 



20449. 10 - * 



1-782 



448-7 



015 



017 



Al-Ou 



7-5643 . 10" 2 



1-590 



565-3 



0-11 



0-12 



G.s.-Cu 



2-0454. 10 _1 



1-684 



2589-9 



006 



0-05 



Average om 



itting Cd-Ou and 



Fe-Hg . 





±0-17 



±0-14 





The exponential equation I have applied to the same data. 

 It has not seemed essential to reproduce here the entire series 

 of data, and the deviations of both equations. They are 

 therefore, presented in a somewhat more digested form. 



* Noll, Wied. Ann. iii. p. 874 (1894). 



