A Knowledge Based Analysis of William Cockburn's Sea Diseases

by ea1234 on October 26, 2017 - 9:59am

    You can find a plethora of rare books on medicine at the Osler library, ranging from Galileo and Aristotle to unknown and bizarre authors. One of those books, is a book written by William Cockburn in 1736, named Sea Diseases. The author was a Scottish physician, that, in his last few years of life, decided to write a book of all of the illnesses and diseases that appear when at sea and their effects. At first glance it is clear that the book was used by people that lived by water, the pages looked as if it were wet at one point, and the leather cover for the book was not just old but deteriorating as we were using it. The book consisted of two parts and an essay, the first part, “a Treatise of their Nature, Causes, and Cure,” is about the treatment of common diseases found at sea. The second part, “Historical Observations of the Sicknesses of the Fleet,” would look at case studies of different men aboard ships and their diseases. This book does not have the format of our regular modern textbooks. Even with the difference of format we were still able to read and understand the book. We can determine that Cockburn’s book follows classic ideologies of the early modern period, such as the four humors, the six non-naturals and the change of gases of the atmosphere when overseas, we can therefore determine that the book does not value progressiveness. However, through the scope of somebody in that period, the two concepts mentioned above work together to “balance” the body and prevent sickness.

    It was believed that when a person would be traveling overseas, the atmospheric air would be different than the one on land. During Cockburn’s time, it was widely believed that the atmospheric air was not just one specific element but a mixture of many different gases. The composition of the Atmospheric air was believed not to be definite; it was believed to be different based on location. The atmosphere would interchange materials with the four humors through the skin. When someone was at sea, this change in gases could easily affect one’s health. It was said that a by simply mentioning the difference in humidity and temperature that is caused by water, one’s health would be substantially affected. We can see that the composition of the atmosphere and its purity would strongly affect the health of the seamen.

    Physicians would also believe that the body would consist of “essential fluids” that would work in conjunction with each other to balance the human body. They consisted of blood, yellow bile, black bile, and phlegm, and they would be called the four humors. Every individual would have a unique balance of each, this is where bloodletting comes from, and if a unbalance occurred, the body will show it through a specific illness. They would also see this through the body trying to get large amounts of essences to leave the body, when a person would have diarrhea or vomit when they are sick would be an example. A seamen’s sickness would usually be based on this excretion of the unwanted humors. Not only the four humors but also the six non-naturals, eating and drinking, walking, sleeping, motion and rest, passions, and evacuation and retention, would be affected. The new routine associated with being a ship would throw off all of these non-naturals, and they would have to find a new balance. Therefore with all of these changes, it is safe to assume that the four humors would become unbalanced when at sea.


    William Cockburn’s book Sea Diseases is focused on the four humors favoring a purer atmospheric condition. Compared to the twenty-first-century we can see the lack of progressiveness in this time period. We can see that the balance of the body is thought to be a crucial thing according to the physicians and the unbalance associated with being at sea was the main thought around Cockburn’s book. This book is still a great source of knowledge for the eighteenth century.


Works Cited


Spary, E.C. Health and Medicine in the Enlightenment. 345-101-MQ: Early Modern Knowledge. edited by Sarah Brand, Eastman, pp. 83-100, 2017.


Cockburn, William. Sea Diseases: or a Treatise of their Nature, Causes, and Cure. Also an Essay on bleeding in Fevers; The Quantities of Blood to be let in any of their Periods.   1736. London.

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