Snow’s book and Poe’s story are based on the same topic—a virulent epidemic—but they differ in their purpose, structure, and tone.
"On the Mode of Communication of Cholera" is an example of a persuasive text that is also expository at times. Snow's purpose is to clearly communicate and argue that cholera spreads through water. In doing so, he provides evidence and statistical data, clarifies some misunderstood notions, and urges readers to consider other factors associated with the disease. His line of argument can be summarized in the following lines:
A little reflection shows, however, that we have no right thus to limit the way in which a disease may be propagated, for the communicable diseases of which we have a correct knowledge spread in very different manners.
. . .
As soon as I became acquainted with the situation and extent of this irruption of cholera, I suspected some contamination of the water of the much-frequented street-pump.
. . .
On proceeding to the spot, I found that nearly all the deaths had taken place within a short distance of the pump.
. . .
With regard to the deaths occurring in the locality belonging to the pump, there were sixty-one instances in which I was informed that the deceased persons used to drink the pump-water.
On the other hand, Edgar Allan Poe's story is a work of fiction in which he personifies the deadly disease that has plagued the city. The primary purpose of his allegorical story is to entertain readers and drive home the message that wealth and power do not protect people from misfortune or death. Poe uses descriptive and vivid language to make his story engaging and entertaining:
It was a gay and magnificent revel. The tastes of the duke were peculiar. He had a fine eye for colors and effects. He disregarded the decora of mere fashion. His plans were bold and fiery, and his conceptions glowed with barbaric lustre. There are some who would have thought him mad. His followers felt that he was not. It was necessary to hear and see and touch him to be sure that he was not. He had directed, in great part, the moveable embellishments of the seven chambers, upon occasion of this great fete; and it was his own guiding taste which had given character to the masqueraders. Be sure they were grotesque. There were much glare and glitter and piquancy and phantasm.
Through his story, Poe also seeks to comment on and criticize the nobility for their shallowness, apathy, and insensitivity toward the masses inflicted with the disease. At a deeper level, Poe shows that wealth and power cannot shield people from life’s major obstacles. In a way, he tries to show that the prince met his end as a punishment for his selfish actions.
