If it's one of the old thermometers and there's a silver liquid inside, it's probably mercury. Most states have banned mercury thermometers. If it's a new one with the colored liquid inside, then usually alcohol from what I understand. When in doubt, call your state's poison control center. I'm sure they can instruct you.
If it's silver and beads, then it's mercury. I don't know how problematic the mercury from a thermometer is, nor do I really know how to properly clean it up.
I've called the poison control center once and they were pretty quick to get on the phone and help. If they can't help, they may be able to direct you to someone who can.
Last edited by Blacklight; 10-24-2012 at 01:46 AM.