in Mercury by Deoxidation. 



497 



To find the effect exerted upon the capillary constant of a 

 common mercurial surface by deoxidation and further oxida- 

 tion, the following experiments were made:— 



A copper wire of 0*3 centim. diameter and 18 centims. long 

 was furnished with a disk 1*7 centim. diameter soldered upon 

 one end. The lower part of the wire and upper side of the 

 disk were varnished, and the under side of the disk kept care- 

 fully amalgamated for some days in order to avoid any change 

 in the degree of amalgamation taking place during the expe- 

 riments ; at its other end, the wire was suspended and cen- 

 tred from the beam of a chemical balance. A vessel of dis- 

 tilled water was then placed under it, the water reaching about 

 1 centim. over the disk. In this position counterweights were 

 put into the scale-pan to balance it. Then mercury was in- 

 troduced into the vessel until it reached and made contact with 

 the amalgamated face of the disk, some of the w T ater being 

 removed to bring it to its original level. Weights were then 

 added to the scale-pan to detach the amalgamated disk from 

 the mercury — that is, to find what column of mercury the 

 outer skin was able to sustain. A similar series was also made 

 with acid water. A battery was then connected between the 

 mercury in the vessel and a platinum wire immersed in the 

 water. The resultant electromotive force of the circuit was 

 measured from time to time to avoid uncertainty through po- 

 larization. 



Mercury being deoxidized. 



Detaching- weig-lit. stiiis. 



Liquid. 



Distilled 

 water. 



/ 9-56 



(9-58 







Dilute sul- 

 phuric acid -i 



Circuit open... — 



f Electromotive force = / 9*65 > 



1-2 Daniellt9"65j 



/ 9-64 | 



°'° » 19-62 J 



n . n J9-65] 



L » liU » 19-65/ 



Circuit open < q r^ V 



f Electromotive force = / 9'81 ) 

 0-47 Daniell 19-83/ 



"9-83 

 < 9 



1-74 



Phil. Mag. S. 5. No. 14. Suppl. Vol. 2. 



mean 9*57 

 „ 9-65 

 „ 9-63 

 „ 9-65 



„ 9-58 

 „ 9-82 



„ 9-83 



„ 9-83 

 2K 



