iron and other ferromagnetic metals do become magnetized in the presence of a magnetic field but it has nothing to do with what the authors are talking about.
It's just that metals are good conductors , both electrical and magnetic, well not all of them but most are.
@ Zapper, yeah you can sure put this thread in history for how NOT to make a reference to something.
But honestly i don't blame the OP because a book like this one can be confusing as hell, so if your not prepared for what you read you can get yourself into a lot of trouble , I have had my expierence in this one too , thank god I realized and turned around to throw out the crap I was once presented from a few guys who were trying to make a Nobel prize ... :D