In her chapter on food poisoning in the Britain of the 1880s and onwards to the present day, Anne Hardy shows how certain agents most poisonous to man have been turned, through laboratory manipulation, into therapeutic agents – an interesting turn on the Paracelsian view of the relation of poisons and medicines. Drug companies, themselves a new kind of business in the nineteenth century, took up much of this investigative role in their laboratories in the case of ergot – ‘a veritable treasure house for drugs’ as one of the main investigators called it – and naturally enough, given their commercial interests, they were very interested in dosage. She also shows that interest in using the botulinum toxin was shown by the US military developing bacteriological warfare, though its most widespread use has been as the cosmetic Botox.