628 



BRIDGMAN. 



TABLE XXI. 



pRKssTRE Coefficient of I^ismtth. 



Other values lor the temperature coefficient between 0° and 100° are 

 0.00429 by v. Aubel,^! and 0.00458 by Lenard.^^ This last is consid- 

 erably higher than any of the above. It is, however, difficult to esti- 

 mate the accuracy which Lenard and v. Aubel ascribed to their own 

 measurements. Lenard and Howard ^^ give without comment as 



g.0.2 



0. 



% 



20° 40° 60° 

 Temperature 

 Bismuth 



80° 



100° 



Figure 24. Bismuth, the average pressure coefficient between and 12000 

 kg. as a function of temperature. 



the coefficient of "analytically" pure bismuth (i. e. bismuth prepared 

 chemically and known to contain some impurity) the impossibly high 

 \alue 0.0052. Lenard, discussing his value 0.00458 for electrolytic 

 bismuth says that he found, "as did v. Aubel," that the temperature 

 coefficient was constant between 0° and 100°. Lenard gives none of 



21 E. V. Aubel, Phil. Mag. 28, 332 (1889). 



22 Ph. Lenard, Wied. Ann. 39, 619 (1889). 



23 Ph. Lenard und J. L. Howard, Electrot. ZS. 9, 340 (1880). 



