Key Terms You Must Know

📖 Key Terms You Must Know

Bills of Mortality

Weekly printed reports listing the number of deaths in each London parish, separated into plague deaths and other causes. They had existed since the 16th century but became especially important during the 1665 plague as a tool for tracking the epidemic's progress. They were compiled by parish clerks and printed by the Company of Parish Clerks. However, they were systematically under-reported: families concealed plague cases to avoid being "shut up," and the searchers of the dead (usually elderly poor women with no medical training) often misidentified the cause of death. Samuel Pepys referred to them regularly in his diary as a barometer of the crisis.

Miasma theory

The dominant medical explanation for plague in 1665 — the belief that disease was caused by "bad air" (miasma) rising from rotting organic matter, swamps, or decomposing bodies. This theory was completely wrong (plague is caused by bacteria transmitted by fleas on rats), but it shaped all government responses: bonfires were lit to purify the air, herbs and flowers were carried as protection, and fumigation was ordered. The miasma theory would not be disproved until Germ Theory was developed by Pasteur and Koch in the 1860s-80s — nearly 200 years after the Great Plague.

Shutting up (house quarantine)

The government measure of sealing infected households — painting a red cross on the door with the words "Lord have mercy upon us" and posting a watchman — for 40 days. The intention was to contain infection. In practice it trapped healthy family members with dying relatives and almost certainly increased transmission within households. People tried hard to avoid being "shut up," which meant concealing plague cases and underreporting in the Bills of Mortality.

Pest houses

Purpose-built isolation hospitals established outside city walls to receive plague victims. They existed before 1665 but were greatly expanded during the crisis. They had very limited capacity relative to the scale of the epidemic and offered little effective treatment beyond isolation. Their main function was separating the sick from the healthy — a correct instinct, even if based on miasma theory rather than germ theory.

Buboes

The characteristic swellings (swollen lymph nodes, usually in the groin, armpits, or neck) that gave bubonic plague its name. They appeared a few days after infection, turning black as they filled with blood — giving the disease its other name, "the Black Death." The appearance of buboes was the visible sign of infection that triggered the shutting-up of a house. Death typically followed within 2-5 days of the buboes appearing; mortality without treatment was approximately 60-70%.

Searchers of the dead

Usually elderly poor women appointed by parishes to examine corpses and report the cause of death to the parish clerk, who recorded it in the Bills of Mortality. They had no medical training and were paid very little — they were drawn from the poorest, most desperate part of society. Their identifications were frequently wrong, which is why the Bills of Mortality systematically undercounted plague deaths.