The Rants, Raves, Gripes, and Prophecies of Paul R. Potts

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Mon, 21 Feb 2005 Mercury

So, I should mention that I have a jar of elemental mercury. I have not weighed it, but I would guess that it contains two or three pounds. It is currently in zip-lock bag, in a tin, padded with foam rubber, on a shelf. It came from my stepfather's basement; I think he probably picked it up from a General Electric salvage lot in the 1970s. He used to bring home all kinds of interesting electronic and mechanical stuff. It was apparently not widely known then that mercury was toxic.

There are a couple of things we could do with this. We could pay someone to dispose of it for us -- probably the safest option. We could donate it to someone setting up an element display. We could just keep it as-is and put off making any decision as to its disposition. Or, we could have it ampouled in some way to make it display-worthy for our own element collection, and keep it locked up until the kids are old enough to be trusted around it.

It is somewhat oxidized and not shiny; this can be remedied by squeezing it through cheesecloth or a coffee filter. But although I used to handle this stuff as a kid, and did the filtering procedure before, I am reluctant to do it in our apartment, especially not with a child and a baby on premises. And then I'd have a cheesecloth or coffee filter contaminated with mercury.

What I'd really like is to find someone who would filter it (to "polish it up") and then put it in a heavy walled and attractive display bottle, top the jar off with argon, and seal it up. This is presumably a dangerous procedure; I don't even know how this kind of thing is safely done, but it must be done often, at least with smaller quantities, because ampoules like this are included in commercially available element displays.

Presumably, you'd need a vapor hood, and would do it wearing protective gear.

If you know someone who would like to take on a project like this, and who would be willing to accept the risk of a mercury spill, get in touch. It would be especially great to find someone who would do it in exchange for splitting the mercury into two jars, keeping half for his or her own element display.

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So, I decided to order a couple of pounds of pure bismuth to melt down with my son, in order to attempt to create bismuth crystals. In case we can't get any visible crystals, I also bid on a really pretty specimen on eBay. We might also see whether crystallization can be improved by using a "seed" crystal. I don't know whether that works with metals or not.

I mentioned cesium as being another metal that would melt in your hand. Well, some web sites describe a couple of other metal elements as being liquid at "room temperature," but really it depends on the temperature of your room. Cesium melts at about 83 degrees Fahrenheit, gallium at 86, and rubidium at 102.

It is a bit odd to talk about the "melting point of francium," since it is an unstable radioactive element that would be insanely difficult or insanely dangerous to accumulate in a quantity large enough to be visible, but the melting point of francium, presumably calculated via mathematical modeling rather than by observation, is listed in the books as 27 degrees Celsius (about 81 degrees Fahrenheit). Bromine and mercury are both liquid at what I think of as comfortable "room temperature" -- around 70 degrees Fahrenheit.

So, this is technically true -- cesium will melt in your hand, but I should probably also point out that when it was done melting in your hand, it would then melt your hand, or, rather, burn its way through it in an extremely painful way. Cesium is extremely hazardous, and pure cesium must be kept under glass in argon. A cesium FAQ list at the University of Rochester says:

"Cesium is an alkali metal, in the same group as lithium, sodium, potassium, and rubidium, and is similarly reactive, but to a much higher degree due to its extreme electropositivity. It reacts explosively with water, and with ice down to -116 C. In air, it catches fire spontaneously and burns with a brilliant sky-blue flame...

Its hydroxide is the most powerful aqueous base known, and will eat through glass, flesh, bone, and numerous other substances."


The FAQ is here:

This is too bad, because it is very pretty; if mercury is quicksilver, cesium could be called quickgold. It would be a beautiful specimen to have in an element collection, but it is far too dangerous to have a specimen, even a nicely ampouled specimen, in the house with small children (or even with me; I would no doubt want to handle it all the time too). Oh, well.

Of possibly more interest are the non-toxic metals with low melting points. More on those when we get our bismuth!

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Lisp Group

I'm looking for people interested in meeting to talk about Lisp, Scheme, and other languages of that ilk. I have set up a group, the Ann Arbor Lisp Languages Meetup; the group home page is here:

As of yet, we have not met, because no one has joined the goup. I'm posting this here in part so that anyone Googling for an Ann Arbor, Michigan, Lisp User's Group, or Scheme User's Group, will find it.

I would also like to get this topic syndicated via RSS onto the Planet Lisp aggregate site (, but as of yet the Lisp content is a little light, so I wait until there is a little bit more of interest here before asking them to syndicate my feed. The RSS feed for this topic is available as:

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