Early Developments The origins of pathophysiology as a distinct field date back to the late 18th century. The first known lectures on the subject were delivered by Professor at the
University of Erfurt in 1790, and in 1791, he published the first textbook on pathophysiology,
Grundriss der Physiologia pathologica, spanning 770 pages. Hecker also established the first academic journal in the field,
Magazin für die pathologische Anatomie und Physiologie, in 1796. The French physician
Jean François Fernel had earlier suggested in 1542 that a distinct branch of physiology should study the functions of diseased organisms, an idea further developed by in 1617, who first coined the term "pathologic physiology" in a medical text. In 1876, upon
Ferdinand Cohn's report of a tiny spore stage of a bacterial species, the fellow German
Robert Koch isolated Davaine's
bacterides in
pure culture—a pivotal step that would establish
bacteriology as a distinct discipline—identified a spore stage, applied
Jakob Henle's postulates, and confirmed Davaine's conclusion, a major feat for
experimental pathology. Pasteur and colleagues followed up with
ecological investigations confirming its role in the natural environment via spores in soil. Also, as to
sepsis, Davaine had injected rabbits with a highly diluted, tiny amount of putrid blood, duplicated disease, and used the term
ferment of putrefaction, but it was unclear whether this referred as did Pasteur's term
ferment to a microorganism or, as it did for many others, to a chemical. In 1878, Koch published
Aetiology of Traumatic Infective Diseases—unlike any previous work—in which, in 80 pages, Koch, as noted by a historian, "was able to show, in a manner practically conclusive, that a number of diseases, differing clinically, anatomically, and in
aetiology, can be produced experimentally by the injection of putrid materials into animals."
Scientific medicine The American physician
William Henry Welch trained in German pathology from 1876 to 1878, including under
Julius Cohnheim, and opened America's first scientific laboratory—a pathology laboratory—at
Bellevue Hospital in New York City in 1878. Welch's course drew enrollment from students at other medical schools, which responded by opening their own pathology laboratories. Hopkins medical school, led by the "Four Horsemen"—Welch,
William Osler,
Howard A. Kelly, and
William Stewart Halsted—opened in 1893 as America's first medical school devoted to teaching German scientific medicine. The laboratory of Rockefeller Institute's
Oswald T. Avery, an early pneumococcal expert, was so troubled by the report that they refused to attempt repetition. During Avery's summer vacation,
Martin Henry Dawson, a British-Canadian who believed everything from England was correct by default, repeated Griffith's results and achieved transformation
in vitro, making it a more precise investigation. At the time of Griffith's report, it was unrecognized that bacteria even had genes. The first genetics,
Mendelian genetics, began in 1900, yet inheritance of Mendelian traits was localized to
chromosomes by 1903, thus
chromosomal genetics.
Biochemistry emerged in the same decade. In the 1940s, most scientists viewed the cell as a "sack of chemicals"—a membrane containing only loose molecules in
Brownian motion—and the only especial cell structures as chromosomes, which bacteria lack as such. Yet the reality of
organelles in cells was controversial amid unclear visualization with conventional
light microscopy. At
Cold Spring Harbor Laboratory in Long Island, New York, Max Delbrück and
Salvador Luria led the
Phage Group—hosting Watson—discovering details of cell physiology by tracking changes to bacteria upon infection with
their viruses, the process
transduction. Lederberg led the opening of a genetics department at
Stanford University's medical school, and facilitated greater communication between biologists and medical departments. In the late 1970s, as president of
Memorial Sloan–Kettering Cancer Center, Thomas collaborated with Lederberg, soon to become president of
Rockefeller University, to redirect the funding focus of the US
National Institutes of Health toward basic research into the mechanisms operating during disease processes, which at the time medical scientists were all but wholly ignorant of, as biologists had scarcely taken interest in disease mechanisms. ==Examples==