509 



[iieseiil a miiforin dislrihutioii of tlie great rest resistance of hi — 

 1922 — l seems strange. 



It also ap|)ears from the tables (cf. also fig. 2) that there exists 

 a ditfereiice of 0,002 degree in vaiiisliing-|)oint teiiiperatnre between 

 //( — 1922— .4 on one side, and Ln — 1922 — // and — III on the 

 other side. An explanation by the assnuiption of differences of tem- 

 perature in tiie lielinm bath seems improbable. As far as the influence 

 of the inner magnetic field is concerned, the windings lie at a 

 distance of 0,4 for [n — J 922 — A, at a distance of 2,2 m.ni. for 

 [n — 1922 — UawA — I [I, in definite parts of cross-section and area 

 of a winding the innei' magnetic field is weakened by that of 

 adjacent windings, and the more so as thej lie more closeij' together. 

 On caicuiation ') this weakening appears, too small to be able to 

 account for the difference found in \anisliing-poinl temperature 

 between /?i— 1922— .4 and ƒ?*- 1922— // and — ///. 



^ 3. Tke supra-conductnig meAals in tke periodic system of the 

 elements. Tiie question rises whether tiie vanishing-point temperature 

 has a periodic characler. In tiie periodic system In lies ai)0\'e 77, 

 S}i above /V; ; it is remarUable that the said tempeiature rises both 

 going from bi to Sn, and from Tl to Pb. Towards the left, from 

 77 to Ry, it, also ascends; if this rise continues, the vatdshing-point 

 tempeiature of Au would lie higher than of Hg. Since An did nf)t 

 become supra conducting on cooling to 1°, 5 K.'), the conclusion might 

 be di'awn that An — perhaps with otliei' metals — can iievei' 

 become so'). 



M Cf. footnote 1, p. 508. 



') Cf. Cotnm. No. 120/>, § 2. 



h In Comin. Suppl. No. 44, p. 35 the possibility is, on the other hand, given 

 that the vanishing-point temperature of Au has not yet been reached on cooling 

 to 1,°5 K. 



