Rust is usually associated with decay. Professor Faraday, however,
observes that, in some cases, it is curious to see how tin, a metal
having a slight attraction for oxygen, protects other metals from
oxidation or rust. In Canada, tin-plate is used for the roofs of houses,
and you are dazzled by the lustre of the setting sun upon the roofs;
whilst there, although it is exposed to the atmosphere year after year,
it does not decay, because the superficial coat of oxide protects the
tin and iron beneath.
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