194 



Holborn and Day — Gas Thermometer at 



For the wire method neither of these courses is open for 

 making determinations in the- absence of oxygen. The bare 

 junction cannot be placed in melted salt on account of its con- 

 ductivity nor exposed to the reducing atmosphere of a plum- 

 bago crucible without danger of affecting the thermo-element. 



Copper. — The melting point of copper was not determined 

 by the wire method on account of the oxidation of the metal. 

 In the crucible, the material used was pure copper in 100 gr. 

 blocks from the Haddernheim Kupferwerli, and determina- 

 tions were made in both oxidizing and reducing atmospheres. 



Table XIX. 

 Melting Point of Copper. 



Date. 



MV. 



Degrees. 



In Oxidizing Atmosphere. 



Nov 



7 

 29 



900 

 330 





F 

 F 



10216 

 10213 



1065-1° 

 1064-8 



7-5 









11-0 



M 



10215 



1065-0 









7-5 



F 



10213 



1064-8 









10-8 



M 



10214 



1064-9 



Dec. 



5 



350 



10-3 



M 



10219 



1065-3 









8-0 



F 



10210 



1064-6 









10-5 



M 



10216 



1065-1 





6 



350 



7-5 



F 



10211 



1064-7 









10-3 



M 



10220 



1065-4 









7-0 



F 



10211 



1064-7 









9-9 



M 



10219 



1065-3 



Mar. 



19 



370 



6-8 



F 



10213 



1064-8 









10-3 



M 



10213 



1064-8 









6-S 



F 



10211 



1064-7 









10-3 



M 



10211 



1064-7 





21 



370 



6-5 



F 



10212 



1064-7 









8-5 



M 



10214 



1064-9 









8-5 



M 



10216 



1065-1 





23 



370 



8-2 



M 



10216 



1065-1 









8-2 



M 



10219 



1065-3 



In Reducing Atmosphere. 



Dec. 7 



355 



7-5 



10-2 



7-2 



10-4 



F 

 M 

 F 

 M 



10442 



1084-3 



10440 



1084-2 



10440 



1084-2 



10437 



1083-9 



(1) In an Oxidizing Atmosphere. — Copper differs distinctly 

 from silver in that when melted in an open porcelain crucible 

 it possesses perfectly definite and coincident melting and solid- 



