Today I want to talk about the role of medical science and the conquest of disease in the developed world. That's a very grandiose title, but it's very easy for us to take for granted the achievements that make the comforts of our everyday life possible—for example, clean water, food that is certified pure, sanitation systems for the easy removal of human waste, immunizations and preventive vaccines that protect us from many infectious diseases. Well, in the 19th century, each of these things were very hard to come by for all but the most privileged, and in the case of immunizations and preventive vaccines, they only became widely available during the last decade of the 19th century. Infectious diseases affected thousands of people every year; therefore the control of these things is one of the great triumphs of modern medicine and public health.
So I want to begin by describing the 19th-century city, and I'm going to use New York City as my case study. New York City in the 19th century was the most diverse city in America. By mid-century it had also the worst health statistics in the nation. Data gathered by the city showed that one out of every 36 people died in 1863, as compared to one out of 44 in Boston and in Philadelphia. New York also compared poorly with London and with Liverpool. New York did not turn its attention to the conditions of its city until the middle of the century. And studies in the 1840s attributed the high rates of disease to the poor housing and also the immoral conditions that certain susceptible or unworthy individuals in communities had created.
In 1864, the New York Citizens' Association organized a district-by-district and block-to-block inspection of living conditions in Manhattan. What did they find? They found that many of the cobblestone streets were very filthy with accumulations of manure from the horses that traversed them. Dead dogs, cats, and rats littered the streets. Household and vegetable refuse collected in the cracks of the cobblestones to the depths of three feet or more in the winter. So-called garbage boxes were rarely emptied, and they overflowed with awful animal carcasses and household waste. There were pools of stagnant water collected in the carcasses of dead animals, and they collected also over sewer drains, and they were generally very clogged. So filth of every kind was thrown into the streets, covering their surface, filling the gutters, obstructing the sewer culverts, and sending forth what were called the "perennial emanations which must generate pestiferous disease."
So filth of every kind was thrown into the streets at all times of the day, and poorly designed sewers had been installed throughout the city, but most of the population depended upon these sort of outdoor water closets and privies in the courtyards of their homes. And in tenement buildings, these privies were often placed very close to the wells that people used to get their drinking water from.
Amenities were very few. These so-called water closets were generally covered and surrounded by filth so as not to be approachable. Others were merely trenches, sunken one or two feet into the ground. And the fluids in some instances were allowed to run into the courtyards. And most houses had no sewers, which made the stench that arose in the summer "absolutely unbearable and perilous," as one observer noted.
Those concerned about the city were most concerned about the stench. I mean, if you can imagine garbage piled three feet high in the streets, this smelled very, very, very, very badly. And so people believed that this stench itself, the smell itself, was the cause of disease. They believed that the garbage in the streets produced these miasmas—that is, the stench that people smelled—and these miasmas sort of polluted the air, spreading across the city, carrying disease with it.