A History of Epidemics in Britain, Volume 1 (of 2) / From A.D. 664 to the Extinction of Plague

by Charles Creighton

The Habitat of the Virus.

We may go even farther in the way of specific probability, and bring the virus definitely to a habitat in the soil. The English sweat, like the Picardy sweat itself, had certain characters of a soil poison, like the poison of cholera, yellow fever and typhoid fever; only it was not endemic like the two last, but periodic, as well as somewhat volatile in its manner of travelling, like dengue, influenza, and others of the “posting” fevers of former times. This brings us to the singular history of the epidemics of sweat in England,—to the clear intervals of many years and the sudden bursting forth anew. What became of the specific virus from 1485 to 1508, to 1517 to 1528, to 1551, and after?

A fresh importation in each of the epidemic years after 1485 is improbable; certainly the circumstances of Henry VII.’s expedition never occurred again, and the traffic between England and her two French possessions of Calais and Guines had nothing in it at all analogous. Equally improbable is the continuance of the sweat in isolated or sporadic cases from year to year throughout the intervals between the epidemics; the only facts that give any countenance to such a continuous succession are the occasionally mentioned “hot agues,” as in 1518, and, on a more extensive scale, in 1539. The seeds or germs of the infection which arose first in London in September, 1485, must have lain dormant in the city until some favouring conditions came round to call them into life. It is impossible to figure such dormancy of the virus except on the hypothesis that it was a soil-poison, having its habitat in the pores of the ground. The periodic activity of all such poisons depends, as we can now say with a good deal of certainty, upon the movements of the ground-water, which in turn depend on the wetness or dryness of seasons. The kind of weather preceding each of the epidemics of the English sweat has been remarked on by writers, but somewhat loosely or erroneously. The peculiarity of the year of the second sweat, 1508, (not 1506 as in Hecker, nor 1507 as in other writers) was a “marvellous” forwardness of vegetation in the month of January, unusual heat from the end of May to the 13th of June, much prized rain on that date, on the 16th, and on the 3rd of July[535], the sweat being heard of first in the Lord Treasurer’s household in July. The third year of the sweat, 1517, began with a great frost from the 12th January, so that no boat could go from London to Westminster all the term time[536], while men crossed with horse and cart from Westminster to Lambeth[537]. This great frost would appear to have been without snow, the whole season from September, 1516, to May, 1517, being chronicled as one of unusual drought, “for there fell no rain to be accounted,” so that “in some places men were fain to drive their cattle three or four miles to water.” The kind of weather following the break-up of the drought is not mentioned, but there is implied of course a certain amount of rain. It was about the end of July or first of August, 1517, that the sweat began in London and the suburbs. The fourth, and perhaps the most severe sweat, that of 1528, followed upon two wet seasons, with one spoiled harvest in 1527 and bad prospects for that of 1528. The winter of 1526-27 had been unusually wet from November until the end of January; then dry weather set in until April; after which the rain began again and continued for eight weeks[538]. The harvest before that seems to have been a partial failure, for early in 1527 corn began to run short in London, and for a week or more there was acute general famine, so that the bread carts coming in from Stratford had to be guarded by the sheriffs and their men all the way from Mile End to their proper market. The high price of corn continued into the summer of 1528. The weather of that summer is not specially recorded for England; but we learn from a diplomatic letter dated, Paris, the 4th of July, that much rain had fallen and destroyed the corn and vines, so that there were fears of universal decay and dearth through all France[539]. On the 5th July, Henry VIII. requests Wolsey to have general processions made through the realm “for good weather and for the plague,” the sweat having already been raging for more than a month. The fifth and last sweat, in 1551, also coincided with an unusually high price of corn, or, in other words, followed one or more bad harvests. In 1550 wheat was at 20 shillings the quarter; at Easter in 1551 the price in London was 26sh. 8d.; ten or twelve ship loads of rye and wheat from Holland and Brittany were sold under the mayor’s direction at a stated but very high price. Meanwhile the sweat was advancing from Shrewsbury to London, where it broke out on the 7th July. The statements of Dr Caius about stinking mists carried from town to town are, like most of his statements, so obviously the product of his uncritical rhetoric that it becomes almost impossible to trust his narrative for matters of fact. But we may go so far as to assume that the first half of 1551 was a season of an unusually moist atmosphere. At all events the fifth season of the sweat, and also the fourth (1528), stand out in the annals as years of scarcity following bad harvests, which had probably failed owing to continuous wet weather.

There is not, on the surface, much uniformity in the weather preceding the epidemics of the sweat in 1508, 1517, 1528 and 1551. In the first of these the winter was mild and the early summer excessively hot and dry; in the second the winter and spring were remarkable for drought, with several weeks of intense black frost in the middle period; in the remaining two the antecedent appears to have been an excessive rainfall. But in all the four we shall find that the law of the sub-soil water, as formulated by the recent Munich school with reference to epidemic outbursts, was exemplified. According to that law, the dangerous products of fermentation arise from the soil when the pores of the ground are either getting filled with water after having been long filled with air, or are getting filled with air after having been long filled with water. It is the range of fluctuation in the ground-water, either downwards or upwards, that determines the risk to health; and in two of the years of the sweat, 1508 and 1517, we find that there had been a rise from a very low level of the wells, while in the other two, 1528 and 1551, the wells had begun to fall after standing for a length of time at an unusually high level. If this reading of the somewhat imperfect data can be trusted, it is at one and the same time an explanation of the outbreak of the sweat in the respective seasons, and a confirmation of the hypothesis that the virus of the sweat had its habitat in the ground. That hypothesis is, indeed, supported by so great a convergence of probabilities, both for the English sweat and for the endemic sweat of France[540], that it may be used to explain the seasonal incidence without laying the argument open to the charge of running in a vicious circle.

Whatever had been the kind of weather determining the successive outbreaks of the sweat, it is clear that the favouring circumstances were in general not the same as those of the bubo-plague. The greater outbursts of plague, as we shall see, were in 1500, 1509, 1513, 1531, 1535, 1543, 1547, and other years not sweat-years. It is only in the autumn of 1517 that the plague overlaps somewhat on the sweat, and even then it becomes noticeable mostly in the winter following the decline of the sweat. The two poisons had existed in English soil side by side, but had not come out at the same seasons; also the sweat had been mostly a disease of the greater houses, and the plague mostly of the poorer.