Constant of Ice and Alcohol at very Low Temperatures. 17 



persion in the case of alcohol for electric radiation lying within the 

 limits of the ten octaves of waves comprised between wave-lengths of 

 8 mm. and 900 cm. measured in air.* 



Table XI. — Determinations of the Dielectric Constant (Specific 

 Inductive Capacity = K) of Ethyl Alcohol by Various Observers. 



Observer. 



Eeference. 



Value 

 found 

 per K. 



Method. 



W. Nernst . . . 

 J. F. Smale . . 

 E. B. Eosa . . . 



W.C.Rontgen 



' Zeits. phvs. Chem.,' 

 toI. 14, i&94, p. 622 



1 "Wied. Ann.,' vol. 57, 

 p. 215 



' Phil. Mag.,' vol. 31, 

 1891, p. 188 



' "Wied". Ann.,' vol. 52, 

 p. 593 



25-8 

 25 -8 

 257 



30-5 



By comparing capacities of 

 condensers with, telephone. 



By deflections of an electro- 

 meter filled with alcohol. 



By attraction between plates 

 of condenser filled with 

 alcoliol. Reversals of E.M.F. 

 2000—4000 per minute. 



B v alternate currents and con- 

 denser (not of such weiglit 

 perhaps as the others here 

 given). 



* The different results found by A. D. Cole for long aud short waves have been 

 ■criticised by J. F. Mohler (see 'Physical Review,' vol. 4, p. 153), who ascribes the 

 differences to conductivity. It has, however, been shown both by E. Cohn and L. 

 Arons (' Ann. der Physik u. Chemie,' vol. 33, p. 13) and by G-. U. Yule that the 

 addition of salts to alcohol, which largely affect its conductivity, does not apparently 

 alter perceptibly the dielectric constant, whether determined by slow or rapid 

 reversals of electromotive force. 



VOL. LXT. 



C 



