Thomas Southwood Smith (1788 – 1861) — sanitary reformer and physician to the London Fever Hospital.
[…] The predisposing causes of epidemics may be divided into two classes—External and Internal. The external are those which vitiate the atmosphere; the internal are those which more immediately vitiate the blood.
[…] The earnest attention which has been recently directed to the first class of causes has led to an advancement in the science of prevention, the importance of which it is impossible to over-estimate. To give only one illustration of the action of a predisposing cause, I select as my example, Overcrowding.
The Statistical Society of London some time ago appointed a Committee of its Council to make a house-to-house examination of the parish of Marylebone, with a view to ascertain how many families in the parish occupied a single room as a living and sleeping room. In the course of this inquiry, one of the examiners came to a house in which there was one remarkable room.
It was occupied not by one family only, but by five. A separate family ate, drank, and slept in each of the four corners of this room; a fifth occupied the centre.
“But how can you exist,” said the visitor to a poor woman whom he found in the room (the other inmates being absent on their several avocations), “how can you possibly exist?”
“Oh, indeed, your honour,” she replied, “we did very well until the gentleman in the middle took in a lodger.”
THE COMMON NATURE OF EPIDEMICS AND THEIR RELATION TO CLIMATE AND CIVILIZATION. FROM WRITINGS AND OFFICIAL REPORTS BY SOUTHWOOD SMITH, M.D. 1866.