The signs given by Willis are as nearly as may be the signs of infantile remittent fever, or worm fever, or febris synochus puerorum, or hectica infantilis, or febris lenta infantum, or an acute fever with dumbness, of which perhaps the first systematic account in this country was given by Dr William Butter of Lower Grosvenor Street, in 1782[11]. It is, he says, both a sporadical and an epidemical disease, “and when epidemical it is also contagious.” The age for it is from birth up to puberty; but “similar symptoms are often observed in the disorders of adults.” Morton, writing in 1692-94, clearly points to the same fever under the name of worm fever (febris verminosa). He adds it at the very end of his scheme of fevers, as if in an appendix, having been unable to find a place for it in any of his categories owing to its varying forms—hectic, acute, intermittent, continued, συνεχής, inflammatory, but for the most part colliquative or σύνοχος, “and malignant according to the varying degrees of the venomous miasm causing it[12].” Butter also recognizes its varying types: it has many symptoms, but they seldom all occur in the same case; there are three main varieties—the acute, lasting from eight to ten days up to two or three weeks; the slow, lasting two or three months; and the low, lasting a month or six weeks. The slow form, he says, is only sporadic; the low is only epidemic, and is never seen but when the acute is also epidemical; it is rare in comparison with the latter, and not observed at all except in certain of the epidemical seasons. Waiving the question whether the remittent fever of children, thus systematically described, was not a composite group of maladies, of which enteric fever of children was one, we can hardly doubt that Willis found a distinctive uniform type in the epidemic of 1661, in Oxford as he saw it himself, in other parts of England by report. It had symptoms which were not quite clearly those of enteric fever: spots, like fleabites, on the neck and other parts, swelling and suppuration of the glands in the hinder part of the neck, effusion of fluid on the brain and in the lateral ventricles, and the intestine free from disease[13].
Confirming Willis’s account for Oxford, is the case of Roger North, when a boy at Bury St Edmunds Free School in 1661, as related by himself in his ‘Autobiography[14].’ Being then “very young and small,” after a year at school he had “an acute fever, which endangered a consumption.” Elsewhere he attributes his bad memory with “confusion and disorder of thought,” to that “cruel fit of sickness I had when young, wherein, I am told, life was despaired of, and it was thought part of me was dead; and I can recollect that warm cloths were applied, which could be for no other reason, because I had not gripes which commonly calls for that application.” That “great violence of nature,” while it had impaired his mental faculties, had sapped his bodily vigour somewhat also, of which he gives a singular illustration.
This special prevalence of epidemic fevers in the summer and autumn of 1661 is noticed also by the London diarists.
Evelyn says that the autumn of 1661 was exceedingly sickly and wet[15]. Pepys has several entries of fever[16]. On 2 July, 1661: “Mr Saml. Crewe died of the spotted fever.” On 16 August: “At the [Navy] Office all the morning, though little to do; because all our clerks are gone to the burial of Tom Whitton, one of our Controller’s clerks, a very ingenious and a likely young man to live as any in the office. But it is such a sickly time both in the city and country everywhere (of a sort of fever) that never was heard of almost, unless it was in a plague-time. Among others the famous Tom Fuller [of the ‘Worthies of England’] is dead of it; and Dr Nichols [Nicholas], Dean of St Paul’s; and my Lord General Monk is very dangerously ill.” On 31 August: “The season very sickly everywhere of strange and fatal fevers.” On 15 January, 1662: “Hitherto summer weather, both as to warmth and every other thing, just as if it were the middle of May or June, which do threaten a plague (as all men think) to follow; for so it was almost the last winter, and the whole year after hath been a very sickly time to this day.”
The great medical authority of the time is Sydenham. His accounts of the seasons and reigning diseases of London extend from 1661 to 1686, so that they begin with the year for which Willis described the epidemic fever “chiefly infestous to the brain and nervous stock,” popularly called the new disease. But Sydenham did not describe the epidemic in the same objective way that Willis did. He records a series of “epidemic constitutions of the air,” the particular constitution of each year being named from the epidemic malady that seemed to him to dominate it most. It was, perhaps, because it had to conform to Sydenham’s “preconceived fancy,” as Lind said, that his account of the dominant type of fever in 1661 differs somewhat from that given by Willis.
Sydenham’s epidemic Constitutions.
Sydenham adopted the epidemic constitutions from Hippocrates, as he did much else in his method and practice. In the first and third books of the ‘Epidemics,’ Hippocrates describes three successive seasons and their reigning diseases in the island of Thasos, as well as a fourth plague-constitution which agrees exactly with the facts of the plague of Athens as described by Thucydides. The Greek term translated “constitution” is κατάστασις, which means literally a settling, appointing; ordaining, and in the epidemiological sense means the type of reigning disease as settled by the season. The method of Hippocrates is first to give an account of the weather—the winds, the rains, the temperature and the like,—and then to describe the diseases of the seasons[17]. Sydenham followed his model with remarkable closeness. The great plague of London has almost the same place in his series of years that the plague-constitution, the fourth in order, has in that of Hippocrates. It looks, indeed, as if Sydenham had begun with the year 1661, more for the purpose of having several constitutions preceding that of the plague than because he had any full observations of his own to record previous to 1665. He is also much influenced by the example of Hippocrates in giving prominence to the intermittent type of fevers. It was remarked by one of our best 18th century epidemiologists, Rogers of Cork, and with special reference to Sydenham’s “intermittent constitutions,” that fevers proper to the climate of Thasos were not likely to be identified in or near London excepted by a forced construction.
Sydenham’s Constitutions.
| Constitutions | Total deaths in London | Plague | Fever and Spotted Fever | Smallpox | Measles | Griping in the Guts | |
| 1661 | “Intermittent” constitution: with a continued fever throughout. | 16,665 | 20 | 3,490 | 1,246 | 188 | 1,061 |
| 1662 | 13,664 | 12 | 2,601 | 768 | 20 | 835 | |
| 1663 | 12,741 | 9 | 2,107 | 411 | 42 | 866 | |
| 1664 | 15,453 | 5 | 2,258 | 1,233 | 311 | 1,146 | |
| 1665 | Constitution of plague and pestilential fever. | 97,306 | 68,596 | 5,257 | 655 | 7 | 1,288 |
| 1666 | 12,738 | 1,998 | 741 | 38 | 3 | 676 | |
| 1667 | Constitution of smallpox, with a continued “variolous” fever. | 15,842 | 35 | 916 | 1,196 | 83 | 2,108 |
| 1668 | 17,278 | 14 | 1,247 | 1,987 | 200 | 2,415 | |
| 1669 | 19,432 | 3 | 1,499 | 951 | 15 | 4,385 | |
| 1669 | Constitution of dysentery and cholera nostras, with a continued fever. | ||||||
| 1670 | 20,198 | 0 | 1,729 | 1,465 | 295 | 3,690 | |
| 1671 | 15,729 | 5 | 1,343 | 696 | 17 | 2,537 | |
| 1672 | Measles in 1670. | 18,230 | 5 | 1,615 | 1,116 | 118 | 2,645 |
| 1673 | Constitution of “comatose” fevers. Influenza in 1675. | 17,504 | 5 | 1,804 | 853 | 15 | 2,624 |
| 1674 | 21,201 | 3 | 2,164 | 2,507 | 795 | 1,777 | |
| 1675 | 17,244 | 1 | 2,154 | 997 | 1 | 3,321 | |
| 1676 | 18,732 | 2 | 2,112 | 359 | 83 | 2,083 | |
| 1677 | Not recorded. | 19,067 | 2 | 1,749 | 1,678 | 87 | 2,602 |
| 1678 | Return of the “intermittent” constitution, absent since 1661-64. | 20,678 | 5 | 2,376 | 1,798 | 93 | 3,150 |
| 1679 | 21,730 | 2 | 2,763 | 1,967 | 117 | 2,996 | |
| 1680 | 21,053 | 0 | 3,324 | 689 | 49 | 3,271 | |
| 1681 | “Depuratory” fevers, or dregs of the intermittents. | 23,951 | 0 | 3,174 | 2,982 | 121 | 2,827 |
| 1682 | 20,691 | 0 | 2,696 | 1,408 | 50 | 2,631 | |
| 1683 | 20,587 | 0 | 2,250 | 2,096 | 39 | 2,438 | |
| 1684 | 23,202 | 0 | 2,836 | 1,560 | 6 | 2,981 | |
| 1685 | Constitution of a “new” continued fever. | 23,222 | 0 | 3,832 | 2,496 | 197 | 2,203 |
| 1686 | 22,609 | 0 | 4,185 | 1,062 | 25 | 2,605 |
The foregoing is a Table of Sydenham’s epidemic constitutions from 1661 to 1686, compiled from his various writings, with the corresponding statistics from the London Bills of Mortality.