J7-13
Shows the Curie point of nickel
A Canadian nickel has the ferromagnetic element nickel as a major part of its composition, and is strongly attracted to a magnet. When heated above its Curie temperature by the gas torch, it loses its ferromagnetism and falls away from the magnet to the pedestal. After a few seconds it will again be pulled up to the magnet.
J7, K1(magnet, bottom), I0