This is a reply to an old letter and summary of reasons for replacing brood
comb.
 
I have a question.If one heats old brood comb to try  recover the wax,it
becomes the foulest mess,   looks like the cells are lined with something,
the round dome ends survive the temperature of boiling water. They are black
and smelly. Is it propolis or is it feces? Any one know.??