In 1859, Louis Pasteur conducted experiments that disproved the theory of spontaneous generation, demonstrating that microorganisms are responsible for fermentation and disease. His work established the foundations of germ theory, revolutionizing the fields of microbiology and medicine. Pasteur's discoveries had profound implications for public health, leading to improved sanitation practices and the development of vaccines.

Pasteur's disproval of spontaneous generation in 1859 shifted literary metaphors of corruption from moral to biological. This influenced Naturalist writers like Zola and Hardy, who depicted characters as victims of invisible hereditary and environmental forces, reshaping the tragic narrative in literature.