are you sure about those nickels? my brain is telling me that they have always been and still are 75% copper and 25% nickel (atleast in modern times, 1907 or something until present day)...
He's talking Canadian nickels.
Years Mass Diameter/Shape Composition
2000–present 3.95 g 21.2 mm, round 94.5% steel, 3.5% copper, 2% nickel plating
1982–1999 (some production until 2006) 4.6 g 21.2 mm, round 75% copper, 25% nickel
1963–1981 4.54 g 21.21 mm, round 99.9% nickel
1955–1962 4.54 g 21.21 mm, 12-sided 99.9% nickel
1951–1954 4.54 g 21.21 mm, 12-sided chrome-plated steel
1946–1951 4.54 g 21.21 mm, 12-sided 99.9% nickel
1944–1945 4.54 g 21.21 mm, 12-sided chrome-plated steel
1942–1943 4.54 g 21.21 mm, 12-sided 88% copper, 12% zinc ("tombac")
1922–1942 4.54 g 21.21 mm, round 99.9% nickel
1920–1921 1.167 g 14.494 mm, round 80% silver, 20% copper
1858–1919