Try This At Home

To figure out who's pot, who's kettle,
no need to use a color chart.
Whichever one is tougher metal,
the clue for telling them apart
is neither color nor complexion;
nor is there need for vivisection.
For the solution, look for sound.
That's where the answer will be found,
because you see, though both may bristle,
too hot to handle without gloves,
do not let pushes come to shoves:
the one will boil; the other, whistle,
and you will see, as like as not,
which one is kettle, and who's pot.