Martinique orders an autopsy on every body thought to be poisoned

Colonial officials in Martinique kept running into the same difficulty. Poison cases produced almost no evidence the law would accept, and courts were often left with the testimony of other enslaved people and nothing else. On 5 November 1749 they answered with an ordinance requiring any slaveholder who suspected that a person or an animal had been poisoned to call a surgeon and have the body opened. The language was urgent. The crime could no longer be ignored, it was real and even common among the slaves, and its spread had to be stopped and if possible pulled up by the root. The ordinance was printed and posted on church doors throughout the colony, and a version of 1758 repeated it and required surgeons to perform the service free so that owners would actually use them. Publishing the law was also a way of spreading the idea the law described.

Between 1750 and 1791 the slave owners of Saint-Domingue lived in fear. A great many of them died of poisoning, and the colonial police could make nothing of it. Selling or preparing suspicious drugs was banned, African magic was banned, and neither prohibition touched the problem. Out of the maroon camps came leaders with reputations for power who announced that the whites would be exterminated and the enslaved set free. Some of them were politicians in every practical sense, working out how independence might actually be won. Their means were the ones available: knowledge of poisonous plants, prepared potions, and charms called garde-corps, body guards, given to rebellious slaves and said to make them proof against weapons and free of any fear of white people. What frightened the planters was that the two things came together. The pharmacology worked and the political programme was serious, and the colony had no answer to either.

Between 1750 and 1775 the sources of Saint Domingue's captive population shifted decisively. Of 218,800 people recorded as landed in the colony in those years, 122,586 came from West Central Africa and Saint Helena, fifty six per cent of the total. The Bight of Benin supplied 52,911 and Senegambia and the offshore Atlantic 8,991, which no longer even made it the third largest source. Earlier in the century the balance had run the other way, with Senegambia a leading supplier and West Central Africa a distant third. Two developments explain the reversal. Governments in the Senegambia region grew stronger and more centralised and shut down the raiding that had fed the market there. In the Kongo region kingship stayed fractured and armed force remained the ordinary way of settling political disputes, so the flow of captives grew as the region came apart.

In 1748 the Virginia legislature made it a felony for an enslaved person to practise medicine of any kind, on pain of death. The act said that many slaves, under pretence of practising physic, had prepared and given out poisonous medicines, and described the resulting illnesses as long and tedious indispositions sometimes ending in death, which is exactly how the earlier accusations had described them. Two provisions softened the sentence. If the court decided there had been no ill intent and no bad consequence it could impose something lighter, in practice a brand on the hand and thirty nine lashes. And the law did not apply where all the owners concerned had agreed to the treatment. Contemporary English law held that poisoning could never be manslaughter because it carried its own evidence of deliberate malice. Virginia dropped the requirement of harm or intent altogether, which let county courts punish people for what they might do.