At the time, the medical community was unaware of the existence of germs and didn’t know how infectious diseases were passed on. As a result, cleanliness was not a factor in surgery, leading to gruesome sights and harrowing results. Surgeons — then regarded as low-status workers and often paid less than the men employed to pick lice off hospital beds — didn’t bother cleaning the blood and guts from surgical tables or their instruments between operations. No one in the operating theater wore gloves, and “it was not uncommon to see a medical student with shreds of flesh, gut or...