Date: Wed, 29 May 2002 11:19:04 -0400

Author: "Jason St. John"

Subject: Re: Weird mercury tube



These descriptions match two tubes that I remembered seeing in deepest
storage here, so I dug them up an tried it. Looks to me like the violent
movements of the little glass bits isn't due to the invisible collisions
that I think of as Brownian motion; the Hg is BOILING, and the roiling
surface of the dense liquid is what kicks around the little glass bits.
My evidence is that the Hg is also recondensing, in the form of small
beads that sit temporarily atop the larger puddle of liquid before joining

More a simulation than a demonstration?
Boston University Physics Demos

On 2002-05-28.10:41 sent:

My understanding of it was that it's designed to show Brownian motion of
particules...the mercury heats up and moves the crystals. I had one around
the lab....I disposed of it as a safety hazard.

John Mocko

On Tue, 28 May 2002, Duane Pontius wrote:

> Greetings,
> We're moving into a new building, which entails plowing through piles
> of weird objects in the demo room that haven't been disturbed for
> decades. One item in particular has everyone puzzled. It's a sealed
> glass tube with a few cc's of mercury and some bluish-purple
> crystals. The tube is supported in a heat-resistant clamp, so I
> presume it was once heated. Anybody have any ideas about what it
> might be good for, or should I consign it for hazardous waste
> disposal? Thanks.
> dp


John Mocko
Senior Teaching Laboratory Specialist (Lecture Demonstrations)
Department of Physics
University of Florida
Gainesville, Fl.