Coherence and Recoherence. 173 
(3) If the cohered wires are sundered and left touching 
with no current passing for many hours, they are sometimes 
found to recohere readily. There is no question of film 
since the surfaces have been in contact throughout the long 
interval. In the fifth case in the above column, coherence 
SSS A.W’ 
SSS as 
A 
Liz 
LLLLL LLL ae eae 
LLL LLL 
Po 
3 
4 7, 
5 oi 
was produced and broken overnight and the wires left in 
contact. In the morning the values Fj, F,... were found. 
(4) Reversal of current. By analogy with magnetism, it 
might be possible to “ wipe out”’ orientation by rapid reversal 
of current of gradually decreasing strength. This was tried 
with no result. 
(5) Mechanical shock and heating. Again, by analogy with 
