•_'"- 



SOLID HYDROGEN. 



former lectures the relation of electrical resistance to temperature has 

 been discussed, and it was experimentally demonstrated that the curves 

 of resistance of the pure metals all pointed to this quality disappear- 



ing or becoming exceeding small at the absolute zero. This fact has 

 been continued, even with the most highly conducting metals, down 

 to the lowest temperature we can command. The experiment illus- 

 trated in fig. 9 shows to an audience the diminution of resistance of 



