Part 5

8. Epidemics resemble each other in the periodicity of their return.

On its first visitation (1485) the Sweating Sickness spread over the whole of England in the course of one year, when it disappeared.

After an interval of twenty years it broke out a second time quite suddenly (1505); revisited nearly all the seats of its former ravages, and again disappeared at the end of six months.

On its third visitation (1517), after an interval of eleven years, it again finished its course within six months.

Its fourth visitation (1528) was repeated after a further interval of precisely eleven years. Such was its violence on this occasion, that the historians of that day designate this period by the significant name of the “Great Mortality.” It drove Henry VIII. from London, destroyed several of the most distinguished persons of the Court, impressed the nation, from the monarch to the peasant, with an awful feeling of the uncertainty of life, continued its destructive course for its accustomed period of six months, and then again disappeared.

From this to its fifth and last visitation, twenty-three years elapsed (from 1528 to 1551.) It then broke out with unmitigated fury, spread once more over the whole of England, ceased within six months, and from that period has never reappeared in any country.

The Oriental Plague of the middle ages returned with a like periodicity; and so it does at the present day in the countries in which it maintains its ancient reign. It recurs with much regularity about every ten years.

The Fever Epidemics of the metropolis return pretty constantly about every ten or twelve years.

The Irish Typhus Epidemics have recurred nearly decennially for the last 150 years.

Epidemic Cholera, on its first visitation, ravaged Great Britain for a period of fifteen months. It then wholly ceased; after an interval of sixteen years it again broke out, and pursued its former course for the same exact period of fifteen months, and then ceased.

Within the brief interval of only five years, it last year (1854) accomplished its third visitation. It now protracted its stay for a period of seventeen months; coming sooner and staying longer.

9. Again, Epidemics resemble each other in the brevity of the space that intervenes between the attack and death.

The Black Death was often fatal on the first day of the attack—generally on the third or fourth. In England it was sometimes fatal within twelve hours, and frequently in two days, particularly when spitting of blood or any other form of hœmorrhage was amongst the early symptoms.

The violent inflammatory fever which characterized the Sweating Sickness, generally ran its course in a few hours; in severe cases, indeed, the crisis was always over within a day and night, but it often proved fatal in six hours.

In our own day we have witnessed many instances in which Epidemic Cholera was fatal within twelve hours. I have known several in which the fatal event followed in ten hours, the patient having been within an hour of the dreaded attack in apparent health.

In all great epidemics the protraction of the disease beyond three or four days is a favourable omen. One of the objects in the treatment of the sick is to gain time. If Nature’s first violent effort to expel the enemy that has taken possession of the system, does not destroy life, the vital powers rally, and the frame often survives the storm.

10. Lastly, Epidemics resemble each other in being produced by the same causes. The whole tenor of experience shows that whatever produces an especial liability to one epidemic, produces a similar liability to every other.

The Causes of epidemics, as of all other diseases, are divided into two classes,—the predisposing and the primary. The predisposing causes are those circumstances which bring the body into a fit state for the action of the primary. The primary cause is the agent which directly and immediately excites the disease.

If a number of persons, in an ordinary state of health, say a hundred, are exposed to the primary cause of any epidemic—to the poison of Cholera for example—probably not more than ten would be seized with the disease. Why do the ninety escape? The poison, by the supposition, encompasses and acts upon all alike: why do ten only suffer? Suppose these same hundred persons took a large dose of arsenic, or an over-dose of chloroform, not only would not one in ten escape, but every individual would certainly perish.

It is conceived that the primary cause cannot take effect unless the system be in a state of susceptibility to its action; that there is in the body an innate power of resistance to all noxious agents of this kind, rendering it, when in full vigour, invulnerable to them; that there are certain circumstances which weaken or destroy this resisting power, and which even impart to the body a peculiar susceptibility to the influence of such agents—and these circumstances are called predisposing causes.

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 vitiators of the atmosphere include overcrowding, filth, putrescent animal and vegetable matters of all kinds, exhalations from foul cesspools, sewers, rivers, canals, ditches, marshes, swamps, &c. Causes of this class are also called localizing, because they favour the generation and spread of epidemics in the localities in which they abound.

The causes which more immediately act from within are those which either directly introduce pernicious matters into the interior of the body, in the shape of foul water or putrescent food; or which indirectly accumulate noxious matters within the system, by impairing the action of the excretory or depurating organs whose office it is to maintain the blood in a state of purity, by removing out of the system substances which having served their purpose have become useless and pernicious.

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.”