with the Mercury Cathode. 



371 



105°. This was followed by heating in the air bath or porce- 

 lain crucible to about 300°, and finally the silver chloride was 

 fused over the tip of a low flame of a Bunsen burner. The 

 results are given in Table 1. 









Table 



I. 







Chlorine 



taken as 



NaCl 



After 

 drying in 

 sulphuric acid 

 desiccator 



Increase in 



After 



drying in 



steam oven 



at 105° 



Weight of 



After 

 heating 



in 

 air bath 



Anode 



After 

 heating 



in 

 crucible 



After 



fusion 



over tip of 



flame 



grms. 



grms. 



grms. 



grms. 



grms. 



grms. 



•1773 



•1809 



•1803 



•1751 







•1745 



•1773 



•1868 



•1801 



•1770 







•1768 



•1775 



•1881 



•1873 





•1784 







•1516 



1663 



•1612 







_ 



•1495 



It is noticed that the constant weights obtained after heating 

 in the steam oven are less than those obtained after the anode 

 had stood over sulphuric acid. Apparently some water was 

 not taken out by the sulphuric acid trying. 



On heating in the air bath or porcelain crucible it is seen 

 that the weights decreased 30 to 90 mgrms. more. On fusion 

 over the free flame further reductions in weight of a few tenths 

 of a milligram were obtained. 



It is noticed, in general, that the increase in weights are 

 nearer the theory after the heating at the higher temperature 

 of the air bath or heating crucible than after the heating at 

 105° in the steam oven. This corresponds to the experience of 

 Yortmann,* the later work of Goldbanm and Smilh,f Gold- 

 baum,:}: and not with the earlier statements of Smith. § 



Increase in Weight upon Heating. — It was noticed that 

 when the anode with its silver chloride deposit was kept at high 

 temperature for long periods the weight gradually increased. 

 In one typical experiment the anode with the silver chloride 

 from 25 em3 of "IN sodium chloride (equivalent to '0877 grms. 

 of chlorine) was heated in the air bath at 320° for about five 

 minutes and weighed. The heating was continued for 11 hours 

 in the air bath for periods from one-half to four hours each, 

 the temperature varying from 400° to 565°, most of the time 

 being about 520°. The anode gradually got heavier, and 

 increased in all "0085 grms. over the first weighing. 



In the porcelain crucible the same effect was noticed to a less 

 degree. For example, the anode covered with chloride equiv- 



*L. c. 



f Jour. Am. Chem. Soc, xxxii, 1469, Nov. 1910. 

 X Jour. Am. Chem. Soc, xxxiii, 42, Jan. 1911. 

 § Electro-Analysis, 305, 1907. 



