POISONING IS NOT A SUBJECT that medieval and early modern legists were reluctant to discuss, and it is mentioned at length in so authoritative a source as the Justinianic Digest, in Chapter 48.8, Ad legem Corneliam de sicariis et veneficiis [Pertaining to Sulla's Law Concerning Murderers and Poisoners]. In medieval Venice, an emporium for herbs and spices for far-flung realms, it was a matter of ethics (not unlike the Hippocratic Oath) that learned herbalists would not administer poisons for any reason. In this period, Venice's speziari, those responsible for mixing herbs and spices in salutary ways to help palliate human ailments, had regulations drawn up for them, just as other guildsmen did. The earliest one that survives is a Capitulary (1268), with separate sections for physicians and for pharmacists, by the Giustizieri Vecchi. Regulation VIII for pharmacists read, ‘Item, non dabo neque dari faciam neque docebo aliquem aliquam medicinam venenosam seu abortivam dare’ [In addition, I shall not give, nor cause to be given, nor shall I instruct someone to give someone any poisonous or abortifacient compound]. Specific political events sometimes dictated legislation on the subject. The Barbo poisoning of 1410, in which a Tatar slave girl was thought to have poisoned her master with arsenic, led to a law dated 22 June 1410 outlawing the sale of eight toxic substances: napellum, opium, cantharides, ‘worms of Caffa’, the arsenic ‘curinum’, arsenic sublimate, silver sublimate and red arsenic by all but two tightly-overseen pharmacies in Venice, that of Due Rughe [Two Wrinkles] and that of San Giuliano on the Rialto.