How We Discovered Germs Cause Disease

By Phin Upham

In 1546, Girolamo Fracastoro began to notice a correlation in epidemic diseases and living conditions. He hard a hard time quantifying exactly what caused the problem, but he described “seeds” that could carry a disease like spores. He felt these spores could be related to chemicals in the world around them, or the clothes and linens people used.

His theory was the first understanding of what we understand today as germ theory. We wash our hands with antibacterial soap, pay for hypoallergenic air filters and invest in cleaning supplies to keep our homes spotless. Back then, families did the best they could with what they had. Human waste was often hauled away from a bucket placed below the home, where it would be tossed into the river.

At the time, there were two prevailing theories. The first was of miasma, or bad air, which would hold scientific sway until the 1880s, when it would be replaced by a fully formed germ theory based on Fracastoro’s ideas. The second was spontaneous generation, which posited that disease simply appeared. This was disproven in 1668, in an experiment using three jars full of meatloaf and egg. By controlling for open air access to the jars, Francesco Redi observed maggots appearing over time on the meatloaf. This suggested some behind the scenes process involving microorganisms, but again showed nothing concrete.

Not until the 1854 Cholera outbreak on Broad Street did the concept of germ theory truly catch on, and even then miasma was still thought of as a logical progression. Germ theory was slow to catch hold, but had to be proven over time. Science never accepts what it sees, no matter how logical things now seem to us.


About the Author: Phin Upham is an investor at a family office/ hedgefund, where he focuses on special situation illiquid investing. Before this position, Phin Upham was working at Morgan Stanley in the Media and Telecom group. You may contact Phin on his Phin Upham website or Facebook page.