Wednesday, 2 December 2015

Eat lead!

I don't suppose that in any Western movie, a beleaguered gunfighter [except Yosemite Sam and Bugs Bunny] has invited his antagonist to "Eat lead, you dirty varmint" but that has become a metaphor for getting shot.  So in that sense lead is bad for the health.  Turns out that it's bad to be at the delivery end as well as, poorly ventilated shooting ranges allow the inhalation of dangerous levels of lead vapour.

The fact that the ancient Romans used lead pipes to deliver water to villa and bath-house has been used to explain the decline and fall of their empire.  The Daily Mail, however, begs to differ. Pewter bowls and tankards [mostly tin but sometimes 4% lead] is also implicated. If the wine contained turns sour it will strip out the lead to maek lead-acetate. It seems likely that the Romans used lead-acetate as an artificial sweetener, and this will be quite enough to induce the symptoms of lead toxicity if consumption becomes habitual. They say that lead compounds taste particularly sweet if you are suffering from calcium deficiency and this has been the cause of lead poisoning among the rickety children of the dispossessed, who picked flakes of lead paint of the walls and furniture and ate them.

Tonight is the 260th anniversary of a fatal encounter with lead which is probably unique in the weird combination of circumstances that caused the demise of an old man.  The Eddystone Rocks are a geological anomaly, out of place and out of time, located 14km of the coast of Devon in SW England.  Lying athwart the approaches to Plymouth and awash at high tide, these rocks have been a hazard to shipping from the time of the Phoenician tin-traders. There have been four attempts to flag the obstruction with a lighthouse.  The first version as designed and built by Henry Winstanley in the 1690s but both maker and artifact were swept to oblivion in the Great Storm of 27th November 1703.  The second essay was designed by John Rudyard and lasted rather longer, at least partly because it didn't have to withstand the storm of the century.  Nevertheless on the 2nd December 1755 a spark, from the naked flames that provided the light, set fire to the wooden roof.  The three lighthouse-keepers tried to put the fire out by throwing buckets of water upwards and while doing this a cascade of molten lead fell on the face and shoulders of  Henry Hall as he looked upwards. The men were unable to control the blaze and rushed downstairs to save themselves on the rock below.  Mr Hall complained to his fellows that his stomach was burning and said that he'd swallowed some of the liquid metal. They were rescued the next morning and treated for their injuries by a local doctor called Spry.  The poor old chap - he was 94 but still working - finally expired from his injuries and the inflammatory response to them after a week of discomfort inside and out.

Dr Spry carried out the autopsy and internal investigations revealed a 200g lump of lead in the stomach.  That sounds like a mugful until you realise that lead is much denser than water and that the ingot was not more than 2x2x5cm in size.  We know exactly how big it was because it was preserved and is now in the collection of a Museum in Edinburgh [interweb sources for details are many and various]. Dr Spry wrote up an account of his case and sent it to the Royal Society, which in those days was a clearing house for wonders. The FRSs greeted the tale with such skepticism that Spry decided to replicate the experiment by pouring molten lead down the throats of dogs and chickens! In an era when being hanged, drawn and quartered was still on the statute books and cockfighting was a spectator sport, offing a few dogs in this way was the acceptable face of scientific enquiry.

Further unbelievable tales in songfrom Eddystone.  BBC 5 minute documentary clip, with added CGI! An unrelated lighthouse mystery.  Weather lighthouses have to withstand.

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