From JIM TEW
Still further to the correspondence about the trouser buttons of Napoleon’s
army (Letters, 12 February, 19 March and 23 April), I wish to remain extremely
critical of reports of common tin changing from shiny metal to grey powder
in conditions where humans can survive.
I suggest that this change will occur only in pure tin. Very small amounts
of metallic impurities will inhibit the process to such a degree that, for
practical purposes, it will not take place.
I am interested in Ralph West’s account of ‘boils’ on organ pipes (Letters,
23 April). Metal organ pipes are almost always made of ‘organ metal’: 30
per cent tin and 70 per cent lead. This is easily worked, does not corrode
and is fairly inexpensive. The front row of pipes may have the proportions
reversed (70 per cent tin and 30 per cent lead) purely for appearance’s
sake. A cheaper pipe can be made of zinc, but this is more difficult to
work. Copper has also been used and a host of other (unsuccessful) experimenters
have tried almost everything else, including concrete.
Jim Tew Oxford
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