and the Weston formal Cell. 



269 



17 per cent, slowly cooled. The temperature was altered 

 comparatively rapidly, the whole range c -40° being gone 

 through in a little less than 8 hours. 



Table IX. 

 Observed E.MJVs = 1*01840 + the differences in 

 hundred-thousandths of a volt, given in the Table. 



Date. 



Time. 



Temp. 



Amalgam. 















17%- 



Slowly cooled. 



17r 

 it t. 



Chilled. 



10 % 



! 



20.5.09 



9.30 a.m. 



0° 



872 



1230 



36 





10.30 



14-52 



467 



825 



21 





11.30 



20-0 



294 



660 









12.30 p.m. 



30-0 



•>•> 



V>:S~^ 



-49 





1.0 



30-0 



6 



33.'! 



-49 





2.0 



30-0 



-8 



333 



-49 





3.0 



35-0 



— 72 



m:> 



-79 





4.0 



360 



-82 



133 



-83 





5.0 



0° 



4-196 



1205 



35 



30.5.09 



9.0 A.M. 



0° 



71 »5 



1222 



36 





1.0 P.M. 



200 



215 



»;. r »o 









3.0 



250 



51 



500 



-23 





4.30 



0° 



791 



1218 



34 



31.5.09 



9.0 A.M. 



o" 



71-2 



1219 



30 





12.30 p.m. 



40° 



-104 



70 



-111 





2.0 



45° 



-142 



-140 



-140 





4.0 



50° 



-ITS 



-182 



-181 



1.&09 



5.0 



0° 



37 





33 



0° 



540 



938 



36 



10.6.09 





o c 



88 ' 



1088 



3G 



10.7.09 





0° 



914 



1113 



36 



It will be observed that the E.M.F.'s of the cells with the 

 amalgams 17 and 17c changed with the rise of temperature 

 from 0° to 20° by almost identical amounts. At 30° the 

 B.M.F. of the cell with the slowly cooled amalgam was 

 near to that of the 10 per cent, amalgam cell, and with 

 increasing time, the temperature remaining constant, the two 

 E.M.F.'s got nearer and nearer together. On cooling to 0° 

 a marked change was evident, the cell with the slowly 

 cooled amalgam having fallen by G*7 millivolts. In 10 days 

 the E.M.F. had risen again within 0*8 millivolt of the original 

 value, and no further change of importance was produced 

 on warming the cell to 25° and subsequent cooling to C . 

 During the whole period the change in E.M.F. of the 



