In early-nineteenth-century England, a good way to get rid of your husband was arsenic. A medical examiner usually couldn’t tell whether the poison was involved, because the symptoms—diarrhea, vomiting, abdominal pain—are much like those of other disorders. Nor could he necessarily place you at the murder scene. The dying typically took hours. Also, you could administer the poison gradually, a little bit every day. In the mid-century, arsenic poisoning was commonly the resort of women. (In 1851, the House of Lords tried to pass a law forbidding women to buy arsenic.) But unpleasant husbands were not the only people you might want to eliminate. During this period of feverish social mobility, a young person might be waiting impatiently for an inheritance, and there was Uncle Ted, sitting on all that money and meanwhile bossing you around, toying with your hopes. In such cases, male poisoners presumably outnumbered females.
The New Yorker