There have been two murders, a vitriol-throwing, a suicide, and several robberies brought about for the sake of this forty-grain weight of crystallised charcoal.
(Adventure VII, pg. 92)
Vitriol, or sulfuric acid, was known since ancient times by islamic alchimists around 900 AD. In 1831, British vinegar merchant Peregrine Phillips patented the contact process, which was a far more economical process for producing sulfur trioxide and concentrated sulfuric acid. Today, nearly all of the world's sulfuric acid is produced using this method.
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