EALPH S. LILLIE 



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vigorous effervescence and lasts for 5 or 6 seconds, as compared with 

 about 1 second at 20°; i.e., the return to passivity is delayed in about 

 the same proportion as the recovery of transmissivity. The disap- 

 pearance of the deposit of dark oxide is also much more gradual. 

 In partly recovered wires the retardation in the speed of the activation 

 wave as it nears its stopping point is more distinct. There are also a 

 larger number of apparently arbitrary irregularities in the distances 



Fig. 4. Curves showing rates of recovery in 65 per cent acid at the two tem- 

 peratures, 20° (Table V), and 3° (Table VI). Ordinates are distances (cm.), 

 abscissae, times as before. 



traveled; thus Wires B and D transmitted for only about 8.5 cm. after 

 16 minutes in the acid, and other reversals in the expected order of 

 the figures are seen in Wires A, C, E, F, and H. Apparently the con- 

 ditions (irregular local circuits, etc.) which interfere with transmis- 

 sion are more effective when the local chemical processes are slower. 

 The points representing the average transmissions at the several in- 



