Iron filings in a pepper pot
The use of iron filings
1 The filings should not be 'dust' but should have one dimension longer than the other two.
2 The 'pepper pot' shaker must have holes large enough to allow the filings of this size to pass through. It can be improvised from a film can with holes through the plastic lid.
3 Iron filings can ruin sinks. It is wise to cover all sinks in the lab before issuing iron filings.
Warn the class to keep fingers away from eyes. Iron filings inadvertently carried to the eyes can damage the cornea.