Silver has been the star performer among precious metals in recent months. But is the vogue for it now getting a little out of hand? Before I began researching this piece, my instinct was to answer that question with a resounding 'yes'. After all, the silver price is now close to levels last reached when the Bunker Hunt brothers (said to be the model for Ewing family in the 'Dallas' TV soap) cornered the market in the course of the 1970s. At the end of the 1980s, at the height of the Hunts' activities, gold was at $850 and silver...