NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Children's land-locked "Sextant"
From: Bill Morris
Date: 2007 Nov 29, 10:47 -0800
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 Hebardwrote: > 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 - --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---