1879 – Thomas Wrigley Grimshaw: from Zymosis to the Bacterial Theory of Disease

Thomas Wrigley Grimshaw

1839-1900

This is a timely piece in medical history due to the transition it represents. Medicine became “Modern Medicine” in the minds of most medical historian once the “germ theory” or what is more appropriately called microbial or bacterial theory of disease came to be. But like any changes in major theories that guide a field such as medicine, this transition did not occur over night. In fact, one could easily argue that several decades had to pass before physicians would fully believe in this new theory and accept the inherent exclusion of previous teachings from their memories on how to practice and from the arguments they developed about why certain diseases existed.

The most common year cited for the development of the microbial or bacterial theory is around 1893, when the four requirements for proving a bacterium to be the cause for illness were demonstrated for the first time for a known disease pattern.

Prior to this event, the bacterial or microbial theory was just a theory, like any other paradigm out there about the possible causes for diseases in general.

Thomas Wrigley Grimshaw’s article demonstrates that the knowledge base requried for the acceptance of the bacterial theory pretty much existed in the late 1870s. In his article published in 1879, he details this new theory, explains it quite fully and constrasts it with the other ongoing paradigms for the time, namely the zymotic theory.

It took medicine and science another 12 to 14 years to be convinced that this new paradigm was a better fit, and that the older paradigm was in fact pretty much false most of the time. This processing of the new findings made from 1879 to 1893 also enabled science to take a closer look at the new germ theory for disease out there–the notion that living beings smaller than animalcules could be the cause.

The interesting thing to note here is that not every disease that today we know fits the bacterial or microorganismal theory was not immediately recognized by this switch in disease philosophies. Diseases like leprosy, STDs, tuberculosis, and a host of others were not placed in the same category as a microorganism induced diseases. Some fungal diseases in fact took a lot of research to even place them in close proximity to this particular disease group. Tuberculosis due to a fungal like growth in the lungs by mycobacterium was one of the hardest to classify next to diseases like yellow fever, cholera, measles and diphtheria. The notion that a small organism could effect the human body in so many different ways was harder for old time physicians to understand.

This article is provided as reading on its own, but is meant to complement the mapping of 5 diseases in the Washington DC area in 1891, reviewed on another page.

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