modulating and supplying to said second electrode an electrode signal obtained from {TAIL ~ a signal generating means} in {HEAD ~ the second liquid container}, 
modulating and supplying to said second electrode an electrode signal obtained from { TAIL ~ a signal generating means } in { HEAD ~ the second liquid container } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH