( 214 ) 



had been found before and after the exposure of the wire to low 

 temperatures — acquired a special xaXne through this peculiarity 



of gold. 



As will appear from what follows, the 2^omt of inflection of the 

 resistance as a function of the temperature must lie much lower for 

 gold than for platinum. Our favourable opinion about gold as a 

 thermometric substance was confirmed with regard to temperatures 

 to a little below — 217°. With respect to the lower temperatures 

 our opinion is still uncertain. A minimum of resistance seems not 

 to be far off at —259°. 



§ 2. The apparatus and the measurements. About the measure- 

 ments we can only remark that they are performed entirely according 

 to the methods discussed in Comm. N". 93. 



The pure gold was furnished through the friendly care of Dr. 

 C. HoiTSEMA. It has been drawn to a wire of 0,1 mm. in diameter 

 by Heraeus. 



The gold wire was wound upon 2 cylinders, it was about 18 m. 

 in length and its resistance at 0° was 51,915 Ohms. The tempera- 

 tures were reached in the cryostat of Comm. N". 94^ as in the 

 investigation in Comm. N". 95^. 



The determinations of temperature were made by means of the 

 resistance of the platinum wire of Comm. N". 95«. The zero 

 determinations before and after the measurements at low tempera- 

 tures agreed to perfection (this agreement had left something to be 

 desired in the measurements dealt with in Comm. N°. 93). 



The measurements were made partly directly by means of the 

 differential galvanometer, partly indirectly by comparing the gold resis- 

 tance with a platinum resistance, which itself had been compared 

 with the originally calibrated platinum resistance (comp. Comm. 

 W. 95^). 



§ 3. The Results, obtained after the direct and the indirect method 

 are given in column 3 of table III and indicated by d and i 

 respectively. 



For the observations the cryostat was brought to the desired 

 temperature by regulating it so that the resistance of the platinum 

 wire had a value corresponding to this temperature, and by keeping 

 this temperature of the bath constant during the measurements of 

 the resistance of the gold wire. The temperatures given in table III 

 are the temperatures on the hydrogen thermometer according to the 

 observations of Comm. W. 95^ belonging to the resistance of the 

 platinum thermometer. 



