In 1861, Louis Pasteur's experiments provided critical evidence supporting germ theory, disproving the long-accepted notion of spontaneous generation. His work demonstrated that microorganisms were responsible for fermentation and disease, transforming the fields of medicine and biology. This advancement laid the groundwork for modern microbiology and hygiene practices, ultimately leading to significant improvements in public health and medical treatments.

Shifted understandings of life, decay, and invisible agents, influencing realist and modernist poetry exploring hidden causes and human vulnerability. Poets such as T.S. Eliot and W.H. Auden incorporated themes of disease and mortality, reflecting the anxieties of their time.