14:6 HoTborn and Day — Melting Point of Gold. 



crucibles entirely, using old ones from which the graphite 

 had been burned away where the reducing action was not 

 needed. 



The gold was melted under two different conditions, either 

 in the reducing atmosphere of a graphite crucible, carbonic 

 acid gas being also sometimes introduced, or in a double por- 

 celain or thick clay crucible (graphite and clay from which the 

 graphite had been burned away), in the presence of atmos- 

 pheric air and later in an atmosphere of oxygen. The gas 

 was introduced into the molten metal through a thin porcelain 

 tube, as described in the experiments with silver (previous 

 paper loc. cit.). Under these two conditions, both melting and 

 solidifying points were observed. 



Table I. 



t 



Date. i MV Degrees. Mean. 

 Graphite Crucible. 



June 21 8-0 F 10194 1063-3 



9-2 M 10197 1063-6 



7-5 F 10194 1063-3 



8-8 M 10197 1063-6 1063'5° 



July 9 6*8 F 10197 1063-6 



8-3 M 10196 1063-5 



6-8 F 10197 1063-6 



8-2 M 10195 1063-4 



Graphite Crucible. Atmosphere of C0 2 . 



July 11 7-2 F 10198 1063-6 



8-5 M 10198 1063-6 



7-0 F 10196 1063-5 10635 



8-2 M 10199 1063-7 



6-8 F 10194 1063-3 



7-9 M 10196 1063-5 



Double Porcelain Crucible. 



June 27 8'0 F 10190 1063-0 



9-0 M 10198 1063-6 1063-3 



7*5 F 10188 1062-8 



9-5 M 10197 1063-6 



Double Porcelain (or Clay) Crucible. Oxygen Atmosphere. 



June 29 7'3 F 10200 1063*8 



8-7 • M 10199 1063-7 



7-0 F 10192 1063-1 



8-5 M 10199 1063-7 



July 12 6-7 F 10189 1062-9 1063*5 



7-8 M 10195 1063*4 



6-5 F 10193 1063-2 



July 13 6-2 F 10198 1063*6 



7-5 M 10203 1064.1 



