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    Re: Children's land-locked "Sextant"
    From: Bill Morris
    Date: 2007 Nov 29, 10:47 -0800

    While we seem to have gone a long way from children's land locked
    sextant, the risks of metallic mercury do seem to have been
    exaggerated. A site that tells you more about mercury than you may
    wish to know is: http://mysite.du.edu/~jcalvert/phys/mercury.htm
    
    Bill
    
    On Nov 30, 7:31 am, Fred Hebard  wrote:
    > This may be related to formation of organic compounds of mercury in
    > the sink traps, unlike the story about the parquet floor in the Royal
    > College of Science, where less formation might be expected.  Organic
    > compounds of mercury are the nasty ones; some are incredibly toxic,
    > on the nanogram or picogram level.  I would expect the mad hatters
    > also were exposed to organic mercurials, being that they were
    > treating hides with them.
    >
    > On Nov 28, 2007, at 8:06 PM, Robert Eno wrote:
    >
    >
    >
    >
    >
    > > Quite a few years ago -- I think it was during a course where we were
    > > learning how to lab pack hazardous waste -- we were told a story
    > > about the
    > > high incidence of minimata disease amongst high school science
    > > teachers. The
    > > cause?  Broken mercury thermometers and the students' practice of
    > > simply
    > > dumping the waste mercury down the sink drain. Mercury being a very
    > > heavy
    > > metal, simply lodged in the sink trap and stayed there for years,
    > > slowly
    > > volatilizing and dispersing in the science lab. The science teachers,
    > > because they spent so much time in the lab, day after day, year
    > > after year,
    > > suffered a much higher than normal body loading of mercury. Result,
    > > short-circuited nervous system.
    >
    > > Unfortunately I do not have a citation for this story but can
    > > probably find
    > > one from a colleague.
    >
    > > Not to dismiss what Geoffrey has written, but in my opinion -- and I
    > > regularly deal with hazardous wastes -- mercury is not something to be
    > > trifled with, nor would I ever recommend it to anyone for use as an
    > > artificial horizon. I may come off sounding like a scared old maid,
    > > but the
    > > world being what it is nowadays; that is loaded with contaminants
    > > of all
    > > kinds, why voluntarily expose yourself to even more?
    >
    > > Robert
    >
    > > ----- Original Message -----
    > > From: "Geoffrey Kolbe" 
    > > To: 
    > > Sent: Wednesday, November 28, 2007 4:08 PM
    > > Subject: [NavList 4154] Re: Children's land-locked "Sextant"
    >
    > >> Gary LaPook wrote:-
    >
    > >>> With use it develops a dross floating on the surface which can be
    > >>> removed by filtering it through a piece of cloth like an old t-
    > >>> shirt.
    > >>> You have to twist the cloth to force the mercury though the cloth
    > >>> and
    > >>> it comes though in shiny little balls leaving the dross in the cloth
    > >>> which I then dispose of. You should probibly wear gloves when
    > >>> handling
    > >>> the mercury like this.
    >
    > >> In the 1960's the old Royal College of Science in London was
    > >> pulled down
    > >> to
    > >> build Imperial College, the British attempt to emulate MIT in the
    > >> United
    > >> States.
    >
    > >> The Spectroscopy labs in the RCS had long been plagued with the
    > >> problem
    > >> that continuum spectra always had absorption lines of mercury on
    > >> them. On
    > >> taking up the parquet floor in the lab, a veritable lake of
    > >> mercury was
    > >> found underneath! As far as I know, all the researchers of that
    > >> era lived
    > >> to a ripe old age, despite working for many years in an
    > >> environment where
    > >> the mercury vapour in the air was probably at saturation point.
    >
    > >> Not that I am advocating that we should not take suitable
    > >> precautions when
    > >> using poisonous substances like mercury - its just that people
    > >> somehow
    > >> seem
    > >> to be more susceptible to such things than they used to be in times
    > >> past.... or, at least, that is the perception.
    >
    > >> Geoffrey Kolbe- Hide quoted text -
    >
    > - Show quoted text -
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