The biggest difference in how somebody’s life looked in the 1870s was how vulnerable they were to diseases. Historians say life expectancy at birth was in the mid-thirties, meaning that the average baby would live only that long. In one way that sounds too gloomy, however. Half of all babies died before the age of five, usually from infections, so if you survived long enough to actually form expectations you faced an average age at death in your mid-fifties. That still sounds depressing to the modern ear, but people could figure how they would beat the odds. Only one childbirth in thirty killed the mother, and your chance of death in combat was growing only slowly from the invention of dynamite (1867). The most dangerous infections tended to come in epidemics—cholera, diphtheria, smallpox—so between times you were safe. Tuberculosis was thought to be hereditary, because the germ was everywhere and susceptibility ran in families. One way or another people found reasons not to worry, until something shook their confidence and their worry mushroomed, then subsided again if only from fatigue. From day to day people didn’t think about disease as much as we think we would.

In the 1800s doctors were learning a lot about diseases by doing autopsies, but they mostly found out what diseased organs looked like, not why they got that way. Sometimes doctors’ hands even carried the disease they were studying to their healthy patients, but medical science knew no reason to suspect this. The discovery of anaesthetics in the 1840s meant diseased organs could be cut out without causing excruciating pain; but this would often lead to infection, and there was no effective treatment for that. Doctors could at least set broken arms and legs to grow straight, as long as the injury didn’t break the patient’s skin. But they knew that a broken bone exposed to air would usually get infected, and the only way to treat a bone infection was to amputate before it took hold. The same was true of bullet wounds that broke bones. Most babies were still delivered without the help of a doctor, but in cities there were doctors who knew how to identify trouble brewing and invervene, for instance by turning around a baby that was heading for the birth canal feet first. But just like surgical patients, birthing mothers were especially vulnerable to infections.

Without infection medicines the sensible treatment was to let the body alone so it could heal itself, and good nursing did this, with rest, warmth, fluids and nutritious food. Unfortunately a natural misconception worked in the opposite direction. Infection caused fever, and it was a good sign when a fever went away. Therefore, maybe fever was an enemy. Some doctor in the distant past noticed that drawing a fair amount of blood would cause someone’s fever to go down. So bleeding became a standard treatment for fever, undermining natural healing and often leading to death. But fevers were often known to cause death, weren’t they? Doctors didn’t figure this problem out until late in the 1800s.

As for what caused infection, there were more than just hints by the middle of the 1800s. Lots of times some kind of human contact was obvious. Ports had long been quaranteening ships that arrived with diseased passengers. When doctors in a Viennese maternity hospital dissected mothers who had died of infection, and right afterwards delivered more babies, a doctor named Ignatz Semmelweiss showed that simply washing hands between times reduced infections (1847). But his colleagues didn’t want to hear that and explained his finding away. When Semmelweiss persisted they put him in a mental hospital. Then in the 1850s cholera was shown to come from wells polluted by neighbors’ excretions. By 1872 specific germs still hadn’t been seen, but a London surgeon named Joseph Lister had begun a campaign for doctors to wash with antiseptics and spray them around the room before procedures. The germ theory of infections remained controversial for years, even after specific pathogens were identified in the 1880s.

The course of learning to be a doctor was much shorter than it is today. You might start by catching the eye of an established doctor and becoming his apprentice, supplemented by taking courses at a medical school to get an MD degree. Bellevue Hospital Medical School required four terms (two years) of lectures, a written thesis, and an oral exam. Of course there was less to teach, and schools weren’t burdened with the academic theorizing that had taken earlier European medical doctors years to master. Even so, you didn’t have to get an MD degree in order to practice medicine; or you could get a degree from any group of doctors who called themselves a. medical school. The government didn’t impose strict standards until the early 1900s.