Foil counterfeiters! Detect metal embedded in genuine US
paper $.
Hold under a glass flask to keep a stirring magnet in place
while you pour out the liquid.
Drop a Nd disk magnet down a 30cm (1') length of copper tubing
& watch what happens. Very neat! or go to magnet accessories
to view our Lenz's law apparatus.
Use them to find iron filings in your breakfast cereal
