Karen Dubos, age 10., of Chestnut Ridge, Pennsylvania, for her question:     

What is quicksilver?

In the past, the word quick meant alive. It seemed a fine word to use in naming a certain silvery metal that runs around like lively drops of water. This metal was called quicksilver. Nowadays almost everybody calls it mercury. Our name for it was borrowed from the Roman god, Mercury. This imaginary fellow was also a lively character. He carried messages for the other gods and wore little wings on his feet to help speed him through his duties.

Mercury, alias quicksilver, is the only metal that stays in a liquid form at ordinary temperatures. All the other metals are frozen solid and refuse to melt even in the hottest weather. Mercury remains liquid and lively until the temperature drops to minus 37 degrees Fahrenheit. This is almost 70 degrees colder than a frosty morning. Then it freezes stiff and solid. The silvery liquid looks like a tempting toy. But handling it happens to be dangerous and all the compounds it forms with other chemicals are poisonous.