1164 



A relation of the second degree as used by Hennlng ^) gives a 

 better correspondence. Holst '), who tested it on an extensive 

 experimental material, found the correspondence satisfactory above 

 about 80° K. But at the temperatures of liquid hydrogen it fails. ') 

 In order to learn the nature of the difference in question measure- 

 ments between 55° K. and 27° K. are thus of great importance, 

 while at the same time they may open up new points of view 

 concerning the dependence of the galvanic resistance on the tempe- 

 rature. By the construction of the hydrogen vapour cryostat an 

 investigation in this range of temperatures had become a possibility, 

 and we have therefore undertaken a series of measurements for 

 the purpose. 



We have extended our results by the addition of a number of 

 measurements outside the range in question, by which we are in a 

 position to communicate data concerning the resistance of gold and 

 platinum running without any intermission through the temperature- 

 range from 15° K. to 273° K. 



§2. Apparatus. F'or the arrangement of our measurements between 

 27° K. and 55° K. we refer to Comm. NM51rt fig. 1, which shows 

 the gas-thermometer and resistances which were used mounted in 

 the vapour cryostat. The measurements outside this range were made 

 in a cryostat which did not differ much in its arrangement from 

 forms which were described on previous occasions. 



The gold and platinum resistances were wound on porcelain tubes 

 with a double screw-thread baked in. The platinum wires were 

 obtained from Heraeus as extremely pure. The gold wires were 

 drawn in the workshops of the Philips's Incandescent lamp factories 

 through new diamonds through the kind intermediary of Dr. G. 

 HoLST. Both to him and Dr. C. Hoitsema, who provided us with 

 pure minting gold for these wires, we extend our sincere thanks. 

 The diameters of the gold and platinum wires were Vio ^^^ Vso of 

 a mm. Before they were used the wires were brought into a 

 thermally stationary condition by being alternately immersed in liquid 

 air and glowed, a few times in succession. One of the platinum 

 wires for which this operation had been omitted showed a consider- 

 able change in its resistance at 0° (J. after the completion of the 

 measurements; the results of the measurements with this wire were 



1) F. Henning, Ann. d. Phys. 40 (1913), p. 635. 



2) G. Holst, Leiden Gomm. N'. 148a, p. 8—3 0. These Proc. XVIII (1), p. 

 833—836. 



') W. H. Keesom and H. Kamehlingh Onnes, Leiden Coram. N". 143, p. 15. 

 These Proc. XVII (2), p. 904. 



