Bills of Mortality and Searchers

Bill of Mortality for September 1665, during the Great Plague.
(Source: Museum of London) 

Bills of Mortality, quite frankly, were the records that identified what the cause of death was for those who died in a certain geographical area.  Think of them as a compilation of the equivalent of our current death certificates, which list the cause(s) of death.  This one is from the week of the highest numbers of deaths during the Plague in London.  It is titled, "The Diseases and Casualties This Week".  The information in the Bills was widely available, as they were published in Gentleman's Magazine, written for intelligent men (Porter, Roy.  "Laymen, doctors and medical knowledge in the eighteenth century: The evidence of the Gentleman's Magazine" in Porter, Patients and Practitioners, 291). They weren't very accurate for two reasons.

The first was that it was difficult to know what was the cause of death.  Think of it, there was no accurate way at that time to tell what was going on inside a body while it was living -- no stethoscopes, no X-rays, no CT scans, no MRIs, etc.  And there was an abhorrence regarding autopsies and dissections, so no easy way to tell what caused the death after it had occurred.

The second is who determined the cause of death.  The city of London was divided into parishes, and each parish church hired elderly lay women who inspected the bodies of the dead and determined what the cause of death was.  They obviously were poorly trained, if at all. (Waller, 96.) 

John Fothergill
(Wellcome Library)

For example, the Quaker physician John Fothergill (one of John Wesley's doctors) wrote in 1768, "These searchers are, for the most part, ignorant poor women ... who, if they see the body emaciated, immediately enter it into their report as consumption."  Obviously, the most likely cause of emaciation was tuberculosis, but cancer or starvation or parasites or several other options can also cause wasting away to death.  Fothergill felt that tuberculosis was thus exaggerated by the searchers as the cause of death and therefore affected the tourist and business trades due to foreigners' belief that London was filled with TB cases (Rusnock, Andrea.  Vital Accounts: Quantifying Health and Population in Eighteenth-Century England and France (Cambridge: University of Cambridge Press, 2002), 139).
Note in the Bill above, the searchers evaluated three people as frightened to death, 15 died of worms, and 121 from problems with their teeth.  The bottom left of the document lists those babies who lived long enough to be christened, which was usually within the first 3-5 days of life (Waller, 52).