The swords came from Gondolin. It probably is what Sam would call "elf
magic," that is, something cool that something elvish-made does that something
not elvish-made doesn't. :) It could be that all the swords of
Gondolin had this power. For a hidden city that always has to be wary in
the chance of its discovery, swords that told you when orcs are near would be
very useful.
Narsil, I believe, glowed white, not blue. I don't know if this is the
same sort of thing,
however.
~*~*~
Greater love has no one than this,
than to lay down one's life for his friends.
John 15:13
