Nissan: coolant on spark plug, blown head gasket, explination

Question
My car ('94 sentra) is missing at all speeds.  I know the problem is with the second spark plug (or at least that chamber).  I have changed the wires and plugs (new -- Bosch) and checked for spark, I've got it.  But while checking for spark, in the second chamber) the engine continued to miss in the same way, but while checking the other wires there was a dramatic drop (down to two firing) in the RPM's.  this has lead me to beleive that it's that specific plug (wire checks on a multi meter).  Now the kicker is that there is an unusual amount of residual coolant on the boot and plug (the second chamber from the right), but if i remember my physics right the spark should arc and at least make the stroke. Is it a internal leak, or another problem?  I have no idea what to do and I don't want to get ripped off.  Is there any explination you can recal?  

Answer
John,

If you have coolant in your cylinder, you may have a blown head gasket, which is allowing coolant to come in from the cooling passages into the cylinder. The coolant is then not allowing the spark to fire, which would explain your miss.

Mike