Snow and Farr Finding the Cause of Cholera

John Snow felt that Cholera was caused by polluted water in which water supplies were contaminated with feces.  In supporting his hypothesis, he opted to conduct his research by the application of logical reasoning.  He was not skilled in the art of scientific matters of a preliminary basis.  However, his conductive reasoning was logical in following a pattern of evidence that proposed to him the findings leading to the cause of Cholera, and its subsequent spread to such a vast percentage of the population.

In his testing of the water from the two companies who provided the water supply, his use of silver nitrate to test levels of salt found in water was ingenious.  It confirmed his suspicions there was something in the water that caused Cholera.  The other portion of his research was performed on the symptoms of those with Cholera and with the remains of those who had succumbed to the disease.  For those living he investigated the physical symptoms that were suffered.  Main symptoms included abdominal pain with gastrointestinal ailments.  Snows thoughts were that the first symptoms of Cholera began with abdominal discomfort.  He thought it to be caused by a morbid material or poison, which acted locally as an irritant on the surface of the stomach (Eyler, 2001).  He felt that this irritant continued in its aggravation affecting the intestines, resulting in vomiting, diarrhea, and dehydration (Eyler, 2001).
Snow was not well versed in epidemiology.  He therefore enlisted the assistance of Farr.  Farr had performed ingenious research on stratagems in accordance with the Cholera outbreak and in supporting his work he documented all confirmed avenues, even creating a law of averages.  This law of averages was a mathematical wonder at depicting percentiles of households that would be affected and the deaths that would ensue in relation to contracting Cholera (Morabia, 2001).

The scientific method that Snow used was to provide a navigational road map in relation to water supplies in and around towns.  He documented regions of locale in which persons were exposed to or dying from Cholera and he earmarked their water source (Eyler, 2001).  This may have seemed a rudimentary design of science for those times.  But it is much like the process Police use when strategically pinpointing suspects per serial killings, to originate the source (or killer in this case).

Morabia (2001) tells us that William Farr (18071883). As Superintendent of the
General Register Office, Englands center for vital statistics was monumental in finding the cause for Cholera.  His sophisticated system involving the collection, classification, analysis, and report on causes of death.  Farr compiled a 300 page report on the 1848-49 Cholera outbreak, tracing the cholera epidemic over time and space and investigated the roles of sex, age, seasons, day of the week and soil elevation (Morabia, 2001).

Farr performed what is known today as surveillance of disease.  This was due to the law of mathematics that could predict the human mortality rate according to soil elevation (Morabia, 2001).  In his surveillance, he was incorrect in his first theory that the disease was caused by fermentation.  Farrs surveillance provided the proof in supporting Snows theory of contaminated water consumption.   The elaborate array of facts which Dr Farr has set forth with so much skill, as the result of great labor and research, will render irresistible the conclusions at which he has arrived in regard to the influence of the water supply in the causation of the epidemic (Morabia, 2001).

Farr contributed the spread of Cholera to the entrance of Zymotic materials entering the body through the lungs.  He stood by this theory in addition to Snows theory of the consumption of contaminated water.  Snow would not have been able to prove his theory on ideas alone, and without Farrs surveillance system, Snows theory would not have been accepted.  Working together yet apart, the works of Snow and Farr resulted in the discovery of the causes of Cholera.  It was deemed that Cholera was transmitted in four ways, that of personal contact, by air, by sewer vapor, and by water (Eyler, 2001).

Snow provided the correct hypothesis yet was unable to prove his theory.  Snow was lacking in appropriate documentation in the overall aspects of all conditions concerned, as his focus was primarily on investigating the routes of the contaminated water supplies.  Although his hypothesis was correct, he had no way of supporting his findings.  Farr was working just as hard as Snow on his own theory of Zymotic conditions, which was not the cause of Cholera, but was a source of exposure.  It turns out that Farrs research and documentation proved invaluable to Snows work.  Working adjacent to each other, they shared their ideas and in a cumulative effort, the cause of Cholera was found.

While Farr did not have a problem in accepting Snows theory of the consumption of contaminated water supplies, Snow acclaimed that Farrs research was simply coincidental by all accounts.  The realization of the importance of Farrs work was overshadowed as Snows theory was accepted when presented with the supporting factors of Farrs work.

This oversight was corrected through time and now Farrs work is recognized as being ingenious in creating a surveillance system of monumental capacity as far as science goes.  This system is the best in existence today.  It has assisted scientists in the continued fight against disease.


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