1802. 8 had measles, one died.

The general testimony in the last quarter of the 18th century is that measles, if a common affection, was not usually a severe one. Heysham, of Carlisle, says that measles came thither in 1786 from the south-west of Northumberland, “where, I am informed, they proved very fatal”; the epidemic began at Carlisle in August, and continued very general until January, 1787, but extremely mild and favourable, only 28 having died (26 under five years, 2 from five to ten), out of “some six or seven hundred, I suppose.” The previous epidemic of measles at Carlisle in 1780 (mortality not stated), had followed a most fatal epidemic of smallpox in 1779; and although the epidemic of mild measles in 1786 did not follow a great epidemic of smallpox, it followed a high and steady annual average of deaths of infants and young children from that cause year after year[1206]. In both years of the measles at Carlisle, there were no deaths from smallpox. In like manner at Leeds, in 1790, measles followed smallpox, and was extremely mild; Lucas wrote of it, “I have not seen one instance of a fatal termination[1207].” This was the time (1785) when Heberden said of the disease in London, just as Willis, Harris and others had said of it and of smallpox together a century before: “The measles being usually attended with very little danger, it is not often that a physician is employed in this distemper.” Increasing mortality from Measles at the end of the 18th century. There were epidemics of measles with high mortality in the 17th and 18th centuries, occurring in special circumstances of time and place, of which instances have been given. But in general the position of measles was not then so high among the causes of death in infancy and childhood as it afterwards became. It is not easy to demonstrate the exact proportions by figures, even for London; the bills of the Parish Clerks are less trustworthy for measles than for smallpox, for the reason that deaths from scarlatina were probably included among the former (see under Scarlatina). For example, the ratio of 1·10 per cent. measles deaths for the ten years 1781-90 in the following table should be only 0·70 if the 793 deaths in 1786, supposed scarlatinal, be left out. But, taking the bills as they stand, they show an increasing ratio of measles (as well as of whooping-cough) among the deaths from all causes towards the end of the 18th century. _Percentage of Measles and Whooping-cough in all London deaths, 1731-1830._ Ten-year Share of Share of periods measles whooping-cough 1731-40 0·70 0·41 1741-50 0·68 0·40 1751-60 1·15 1·03 1761-70 1·11 1·12 1771-80 0·93 1·66 1781-90 1·10 1·32 1791-1800 1·34 1·97 1801-10 3·11 3·14 1811-20 3·52 3·49 1821-30 3·17 3·13 During the same period, the ratio of deaths from all causes under two years of age had decreased, while the ratio of deaths from two to five, and at all ages above five, had increased as in the following table, also compiled from the London bills beginning with the year 1728 when the ages at death were first published. _Ratios of Deaths from all causes under two years, from two to five, and above five, London, 1728-1830._ Ratio Ratio Ratio of Total under from all ages Period deaths Two years Two to Five above Five 1728-30 (3 yrs.) 84,293 36·7 8·7 54·6 1731-40 246,925 38·6 8·9 52·5 1741-50 254,717 33·6 7·9 58·5 1751-60 204,617 30·9 9·3 59·8 1761-70 234,412 34·1 9·1 56·8 1771-80 214,605 34·4 9·6 56·0 1781-90 192,690 32·5 9·5 58·0 1791-1800 196,801 31·8 10·9 57·3 1801-10 185,823 29·3 11·5 59·2 1811-20 190,768 27·7 9·8 62·5 1821-30 209,094 28·0 9·7 62·3 Thus, while measles (with whooping-cough) was usurping, so to speak, a larger share of all the deaths, the two first years of life were claiming a smaller share of the deaths from all causes as the probability of life was improving. The saving of infant life was due to various things, but especially due to the decline of smallpox, as described in another chapter. We may now turn to consider, by a less abstract method, the increase of measles mortality from the last years of the 18th century. In Willan’s periodical reports of the prevailing diseases of London[1208], scarlatina declined in 1795 and became sporadic, after having been extremely fatal for a long period, while measles and smallpox began to extend about the end of that year, the former being for the most part mild in its symptoms and favourable in its termination, the latter often confluent, and fatal to children. The report for March and April, 1796, is that measles had become more severe, and had been followed by obstinate coughs; for May, that “smallpox and measles have prevailed more during this spring than has been known for many years past.” However, it was smallpox that occasioned the larger share of the deaths among infants and children. The next general view that Willan gives us of the relative importance of measles among the infectious diseases is under Oct.-Nov. 1799: “The measles, though extensively diffused, have continued mild and moderate. The scarlet fever has increased, since the last report, both in extent and in the violence of its symptoms; but the contagious malignant fever [typhus] has been the most frequent, as well as the most fatal, of all acute diseases.” There is little sign of fatal measles in the London bills during the years of distress, 1799-1801; but we hear of it in Scotland and Ireland, where there was probably less scarlatina. An Edinburgh observer of the prevailing diseases says that “several hundreds” died of measles there in the winter of 1799[1209]. In the Irish emigration to America, which took one of its periodic starts owing to the repressive measures following the rebellion of 1798 and the union with England, measles appears to have been the fatal form of infection among the children on board ship. A medical letter from Philadelphia, 10 December, 1801, says that measles had been imported to Newcastle and Wilmington in the summer of 1801 by some vessels from Ireland, on board which a great many children died during the voyage; the epidemic at length reached Philadelphia and had become general throughout the city[1210]. At Whitehaven large numbers of infants were attended in measles from the Dispensary in 1796 and 1799, but the deaths (2 in 202 cases, and 2 in 266 cases) are probably only a few that came to the knowledge of the visiting physician. An epidemic at Uxbridge, Middlesex, in the winter of 1801-2 was certainly malignant or fatal more than ordinary, whatever its anomalous type may have meant. The epidemic began in September, and was at first of so mild a type as to need no medical assistance. Towards November the cases increased in number and severity, but still, says the narrator, “I believe every case terminated favourably, not in my practice only, but in that of other gentlemen also.” Towards the middle of November, the attacks were more sudden and more violent while they lasted, and were soon over either in death or recovery. In some the eyes became all at once as red as blood, the pulse full, quick and hard, the cough incessant, with a rattling noise in the throat and quick laboured breathing, the skin hot and parched. “Another peculiarity in this epidemic was that the cuticle in many children did not separate after the disappearance of the eruption, and in several others that I particularly noticed, it came off in large flakes instead of branny scales; and the appearance of the rash in others assumed so striking a resemblance to the scarlet fever that, had it not been for the violent cough and other measly symptoms, many such cases occurring singly might, upon a superficial view, have been considered and treated as that disorder.” The various forms occurred in the same family; thus, of four children, one had typical measles, ending in a branny scurf, two others had the sneezing and the watery inflamed eyes, but the eruption in the form of an universal red fiery rash, after which the skin peeled in large flakes, while the fourth had the disease of a low typhoid type and recovered with difficulty. The epidemic “continued its destructive career” through December and January, after which the type became as mild as it had been at first. If the author had not discussed the diagnosis as between measles and scarlatina, deciding in favour of the former, one might have suspected that there were cases of both. But even the sphacelation that followed the application of blisters, the pemphigus-like eruption turning gangrenous, and the petechiae, were signs of malignancy in more than one of the exanthematous fevers. The sequelae of this epidemic of measles were as anomalous as the symptoms themselves; instead of the inflamed eyes, and the distressing cough (sometimes ending in consumption) there were aphthous fever and dysenteric purging[1211]. The deaths in the London bills for the first twelve years of the century will be found in the table on p. 655. We find the measles deaths for the first time equalling the smallpox deaths in 1804, and in 1808 surpassing them, and we may take it that the deaths so entered were almost wholly of measles proper. The epidemic of measles in 1807-8 was, in fact, a great and clearly defined event in British epidemiology, the first of a series of epidemics in which that disease established not only its equality with smallpox as a cause of infantile deaths but even its supremacy over the latter. It would appear, also, to have been more malignant than the scarlatina that coexisted with it. Thus, Bateman, of London, at the outset of the great measles epidemic of 1807-8, says: “The most prominent acute disorders have been eruptive fevers and particularly the measles, which during October and November have been very prevalent, and, when occurring in young children, have proved very fatal by terminating in violent inflammation of the organs of respiration.... The scarlatina was generally mild, presenting the eruption with a slight sore-throat[1212].” Other accounts of the epidemic in London show it to have been of the type which Sydenham, in 1674, called anomalous or malignant. The epidemic began in October-November, 1807, and was remarked as unusually fatal[1213]. Several children in the same family had fallen victims to it. Some cases were fatal in a few days, either from the intensity of the fever or from pneumonic complication. “But when these symptoms have been less violent, and the patient has passed without much alarm through the different stages of the disorder, and even after all apprehension of danger in the mind of parents or friends has been dismissed, a continuance or recurrence of pneumonic symptoms has laid a foundation for phthisis pulmonalis.” In some cases attended from the Westminster Dispensary, death followed from effusion into the chest or from membranous inflammation of the trachea. Numbers who recovered from the measles were afterwards affected with debility, cough, emaciation and oedematous swellings of the face and extremities which proved very difficult to remove. These particulars are given mostly for the end of 1807, but it is under the year 1808 that the great rise in the measles deaths appears in the London bills of mortality. Besides these accounts for London, we have some details of the same epidemic at Edinburgh and Aberdeen and exact figures for Glasgow. It began at Edinburgh in the winter of 1807, and at Aberdeen (as at Glasgow) in the spring of 1808. At both places it was remarked as unusually fatal, chiefly from a complication of bowel complaint in children and from pulmonary affections in adults. The Aberdeen observer says that in town (the disease being milder in the country) there were troublesome symptoms in almost every case--a violent pain in the belly, frequently accompanied with diarrhoea (and even with vomiting), and with the dysenteric symptoms of tenesmus and mucus in the stools. This bowel complaint usually lasted three or four days, and wasted the patients remarkably. There was also the usual catarrh with violent tickling cough, and, after the acute attack, a tendency to sudden dyspnoea and “fatal coughs.” In some the convalescence was lingering and very distressing to the patient: “it consists in a slow kind of fever, with evening exacerbations[1214].” The observers at Edinburgh and Aberdeen agree that the epidemic was the worst that had been seen for many years. Says the former[1215]: “I believe that the present epidemic has been more general in this place and its vicinity than ever happened within the remembrance of any medical man at present living, and I am sorry to say it has been very fatal.” The Aberdeen chronicler says the mortality was “greater than we have witnessed for a long period,” and that the epidemic was general throughout the whole of England and Scotland. But, besides this direct testimony, there is a not less indirectly significant fact of the epidemic. It affected many adults--“persons of all ages, who had never had them,” says the Aberdeen writer: few persons escaped, says the Edinburgh observer, “who had been previously unaffected by this disease.” The deaths from pulmonic complaints did not often happen among children, but among people somewhat advanced in life. Significant also was the outbreak in the Invernessshire Militia, which marched into Edinburgh in March while the epidemic was raging. Fifty men, all young recruits newly joined, were attacked in the course of a few days, the others escaping the disease though equally exposed to it; in some of those who died in the regiment there were found, on opening the thorax, fibrinous pleurisy and pericarditis, with effusion of fluid, as well as evidences of bronchial catarrh[1216]. The Aberdeen writer says: “I always observed that in full-grown persons the eruptions were more numerous, quicker in appearing, and longer in going off than in young subjects.... Many full-grown persons were very ill, yet the measles were more fatal to the young.” The implication of so many adults in the severe epidemic of 1808 would of itself show that measles had not been for some time before a steady and universal affection of infancy and childhood[1217]. Measles in Glasgow in 1808 and 1811-12: Researches of Watt. The measles epidemic of 1808, which appears to have been somewhat general in England and Scotland, made an extraordinary impression in Glasgow. That disease had never before been nearly so mortal there, nor had any infection since the time of the plague, not even smallpox itself, engrossed the burial registers so much as measles did in the months of May and June, 1808. Glasgow had been the worst city in the kingdom for smallpox; by a somewhat sudden transition the infancy of the city died for a few months in larger numbers by the new disease than by the old. The highest monthly mortalities from smallpox had been 114 in October and 113 in November, 1791, the population being 66,578; but in 1808, the population having increased to 100,749 by the census of 1811, measles carried off 259 children in May and 260 in June, and in the months before and after as follows: _Measles in Glasgow, 1808._ Month Deaths Jan. 2 Feb. 2 March 5 April 71 May 259 June 260 July 118 Aug. 32 Sept. 22 Oct. 10 Nov. 4 Dec. 2 The figures were not known at the time; but every doctor in Glasgow, as well as the whole populace, knew that measles was cutting off the infants, while smallpox had fallen to insignificance. So dramatic was this turn in the public health that the common people set it down to the new practice of inoculating children with cowpox: ready to believe anything of vaccination, they concluded that, if it kept off smallpox, it brought on measles. Dr Robert Watt took the trouble to refute this singular notion; he found in his own practice that three children in one family, and in another two, had died of measles who had neither been vaccinated nor had smallpox before. Another great epidemic of measles arose in Glasgow three years after, in the winter of 1811-12: Measles 1811 deaths October 12 November 76 December 161 1812 January 130 February 61 March 30 April 19 May 15 June 18 Those two great epidemics of measles in Glasgow, in 1808 and 1811-12, were the occasion of one of the earliest and most memorable inquiries in vital statistics in this country, the research by Dr Robert Watt on “the Relative Mortality of the Principal Diseases of Children, and the numbers who have died under ten years of age in Glasgow during the last thirty years[1218].” Having begun with a search of the principal Glasgow burial-registers for deaths by whooping-cough, he extended it to sixteen folio volumes of the registers of all the burial-grounds, old and new, and included the mortalities from all causes with the ages at death, and from fevers and the principal diseases of infancy and childhood. The increase of population from 1783, when his figures begin, to 1812, the date of his writing, was known to him; but as the numbers living at the respective periods of life were not known, he was obliged to state the change in the mortalities at the various ages, and from the various diseases, in ratios of the annual deaths from all causes,--a perfectly scientific comparison so long as the nature of the ratios compared was clearly stated. It would have been more satisfactory, of course, if the comparison could have been made in terms of the annual death-rate, which was much lower (for reasons already explained), in the second half of his period than in the first; but, in the circumstances, that was impracticable, and Watt did the next best thing. The following is the principal part of his table of ratios in five successive periods of six years each: _Vital Statistics of Glasgow in sexennial periods, 1783-1812._ (_Watt._) Per Per Per cent. cent. Per Per Sum cent. from from cent. cent. of all under Two to Five of of Period deaths Two Five to Ten Smallpox Measles 1783-88 9994 39·40 10·66 3·42 19·55 0·93 1789-94 11103 42·38 11·90 3·79 18·22 1·17 1795-1800 9991 38·82 12·21 3·45 18·70 2·10 1801-06 10304 33·50 13·43 5·10 8·90 3·92 1807-12 13354 35·89 14·22 5·58 3·90 10·76 Per cent. of Per cent. of Period Whooping-cough “Bowel-hive” 1783-88 4·51 6·72 1789-94 5·13 6·43 1795-1800 5·36 6·47 1801-06 6·12 7·27 1807-12 5·57 9·26 The actual deaths from smallpox, measles and whooping-cough are shown in the next table, which includes for comparison the corresponding figures from the London bills of mortality: _Smallpox, Measles and Whooping-cough in London and Glasgow, 1783-1812._ London /----------------------------------\ Year Smallpox Measles Whooping-cough 1783 1550 185 268 1784 1759 29 457 1785 1999 20 194 1786 1210 793 200 1787 2418 84 228 1788 1101 55 298 1789 2077 534 374 1790 1617 119 391 1791 1747 156 279 1792 1568 450 311 1793 2382 248 352 1794 1913 172 469 1795 1040 328 311 1796 3548 307 536 1797 522 222 567 1798 2237 196 418 1799 1111 223 451 1800 2409 395 380 1801 1461 136 428 1802 1579 559 1004 1803 1202 438 586 1804 622 619 697 1805 1685 523 703 1806 1158 530 623 1807 1297 452 439 1808 1169 1386 326 1809 1163 106 591 1810 1198 1031 449 1811 751 235 486 1812 1287 427 508 Glasgow /----------------------------------\ Year Smallpox Measles Whooping-cough 1783 155 66 153 1784 425 1 41 1785 218 0 34 1786 348 2 173 1787 410 23 57 1788 399 1 17 1789 366 23 45 1790 336 33 177 1791 607 4 117 1792 202 58 68 1793 389 5 112 1794 235 7 51 1795 402 46 180 1796 177 92 60 1797 354 5 76 1798 309 3 98 1799 370 43 95 1800 257 21 27 1801 245 8 125 1802 156 168 90 1803 194 45 60 1804 213 27 52 1805 56 90 129 1806 28 56 162 1807 97 16 85 1808 51 787 92 1809 159 44 259 1810 28 19 147 1811 109 267 62 1812 78 304 103 The ratio of deaths under the age of two had decreased greatly in Glasgow, while the ratios from two to five and from five to ten had increased. At the same time smallpox had almost ceased (but only temporarily, as it appeared) to be the great infectious scourge of infancy, while measles had come in its place. “Now that the smallpox are in great measure expelled,” (Watt believed that cowpox inoculation had done this), “the measles are gradually coming to occupy the same ground which they formerly occupied. I am sorry to make this statement, but the facts, at least with regard to Glasgow, are too strong to admit of doubt.” In order to explain the enormous increase of deaths by measles, he had recourse to the following argument. Formerly nearly all children, say nine-tenths, had both smallpox and measles, the attack of smallpox in most cases coming first. Children who had survived smallpox were fortified by that ordeal, not merely as selected lives, but positively fortified, so that measles, when it assailed them in due time afterwards, was taken mildly or was “modified,” not one in a hundred cases proving fatal. But now (1813), when so few children have been through the smallpox, measles has become ten times more fatal to them, although it could hardly be more common than it used to be. Having found it necessary to assume that children in former times took smallpox before they took measles, nine-tenths of them taking both, he qualifies this in another passage: “Still, however, as the measles came round now and then, as a very general epidemic, they must occasionally have had the precedence, and it was perhaps chiefly among such patients that the disease proved fatal.” The measles which came round now and then as a general epidemic was nearly the whole of it; even in London there were intervals of several years with only a few annual deaths, and in smaller towns or country districts the clear intervals were longer. The prevalence of measles on the great scale being more casual than that of smallpox, it is likely that most children had taken smallpox before they incurred measles. But it is clear from such instances as the London epidemic of 1674, and the epidemic in the Foundling Hospital in 1763, that measles might attack children just before smallpox, and by its weakening effects, increase the number of victims of the latter. As to the fatality of measles itself in the 17th and 18th centuries, the statement of Watt that it did not amount to one death in a hundred attacks, while it can neither be proved nor disproved by an array of figures, can be shown to be inconsistent with the language of annalists. The epidemics of measles varied in severity then as afterwards: that of 1670 in London was regular and mild, that of 1674 in the very same months of the year was anomalous and fatal; Huxham characterizes the measles at Plymouth in the winter of 1749-50 as “maximé epidemici, imo et saepe pestiferi”; at Kidderminster, in 1756, after fevers had been very fatal to adults, the measles went through the town so that an immense number of children “died tabid”; in the West of England about 1760 a disease called measles made “a melancholy carnage amongst children.” While Watt’s theory of the working of this principle of substitution is open to criticism on some points of detail, the law itself, as enunciated by him, remains to the present time one of the soundest and most instructive generalities in epidemiology. He based it upon a laborious search of the burial registers, such as no one before him in this country had undertaken. Next he saw correctly that a great rise in the deaths of infants by such a disease as measles could only be accounted for by a great increase in the rate of fatality. Thirdly, he connected the loss from measles with the saving from smallpox. Adopting an old opinion, which may be discovered in Willis[1219], he argued that smallpox, when taken first, served to fortify children so that they passed easily through the measles afterwards; but in the following passage he indicated a better reason why the absence of smallpox gave measles the chance of proving more fatal: “In this point of view we are not to consider the smallpox as so peculiarly fatal in their nature. They perhaps prove so fatal merely by having the start of other diseases. The measles, the chincough, the croup, the scarlet fever, and perhaps many others, would have proved equally fatal had they occurred first.” The principle is true to this extent, that a certain proportion of weakly infants, or children of poor stamina, will succumb to almost any disease--if not to smallpox, then to measles, and if not to measles directly, then to the sequelae of measles. This was perceived in the form of a necessary truth by Haygarth in 1793: “A considerable number of those who now die of the smallpox would die in childhood of other diseases if this distemper were exterminated[1220].” It was commonly believed that smallpox had at length found its real artificial check, not in the inoculation of itself, but in the inoculation of cowpox. At all events it had declined greatly in Glasgow. During the three years before the measles epidemic of 1808, there could hardly have been more than a thousand children attacked by smallpox, or not one in ten of all the children born. During several years the infancy of the city had been spared any great ordeal of infectious disease; the first epidemic that came along happened to be measles, so that it fell to that infection to take off the weaklings. In the economy of nature it is impossible to rear all the young of a species, nor would it be good for the species if it were possible. It is among the birds that the principle of population, or of the survival of the fittest, is seen working in the most admirable way: the annual migration of many species to breed in a remote country brings with it an ordeal for the birds of the year in finding their way to the winter feeding-grounds--an ordeal which only the strongest come through. For some unexplained reason, the young of the human species are peculiarly tried by infectious diseases, which multitudes pass through safely, while many of poor stamina or of ill tending are cut off. Dr Watt’s teaching, as to the displacement of one infectious cause of death by another was resisted at the time as being of “evil tendency” for the pretensions of vaccination, although Watt believed as firmly in the virtues of cowpox as Jenner himself did. Writing to James Moore on 6 Dec. 1813, Jenner says of Watt’s essay (Baron, II. 392): “There is nothing in its title that developes its purport or _evil tendency_.... Is not this very shocking? Here is a new and unexpected twig shot forth for the sinking anti-vaccinist to cling to.” Sir Gilbert Blane, who was then president of the Medical and Chirurgical Society, having a natural fondness for ideas of all kinds expressed in a paper to that society rather more approval of Watt’s view than was thought prudent: “An ingenious friend of mine has remarked to me in conversation that some light is thrown on this subject by considering that whichever of the epidemic maladies attack children first, it will be the most fatal, inasmuch as all feeble constitutions will fall in its way while the stronger will be left to encounter the attacks of the others; and that the smallpox, owing probably to the greater abundance and rankness of their effluvia, are generally caught in a casual way before measles, hooping cough and scarlet fever, and are therefore reckoned more fatal than any of these. But, a new field of research being opened,” etc. Efforts were made to correct the effect of this, by showing that measles in some parts of the country had not been more fatal than usual. Holland, of Knutsford, attributed the fatality of the epidemic in 1808 to a change of the wind to the east. Writers in the _Edinburgh Med. and Surg. Journal_, pointed out that Watt had compared the absolute deaths by smallpox at one time and by measles at another without taking account of the increase of population, and the rates of mortality from each disease. The best criticism of Watt was by Roberton in his _Mortality of Children_, 1827, p. 49. He offers the following considerations, without seeming to know that they were really to be found in Watt’s own essay: Smallpox used to be caught first; it swept off the feeble and sickly, leaving the strong and vigorous _only_ to encounter the attacks of other diseases. “That infectious febrile disease to which in early infancy there is the strongest predisposition will of course in general make the first attack and prove the most fatal of any.” There were reasons why measles used to have comparatively few victims, “and why, when they now prevail epidemically, they, as was the case with smallpox, are caught at an earlier age than other diseases in general and prove so very fatal: which happens not more from their priority in attack than from being in their nature what they were ever considered--a severe and dangerous disease. We are to recollect, however, that measles do not in general attack at so early an age as smallpox; nor ever, like the latter, destroy eight or nine-tenths of all the children that die in the place where they happen to prevail, as was the case in the variolous epidemics of Chester and Warrington [this is an error, _vide supra_, p. 554]; consequently we have reason to hope that neither measles nor any other infantile disease will, as Dr Watt imagined, ‘come to occupy the place which smallpox once occupied,’” (p. 58). A feeble echo of Roberton’s criticism, with all its scientific candour left out and its points against Watt emphasized in a spirit of paltry cavilling, was heard next year in the Goulstonian Lectures of Bisset Hawkins on _Elements of Medical Statistics_, 1829. Many years after, when the enormous increase of deaths by scarlatina was illustrating the doctrine of displacement in a new way, Dr Farr gave a full analysis of Watt’s essay in his annual Letter to the Registrar-General for the year 1867, and endorsed the Glasgow teaching of 1813 with more heartiness than it had hitherto received. Although Farr did not take the Malthusian view that the loss of weakly children by one means or another was inevitable, yet he could not help seeing, in his work upon the registration returns from 1837 onwards, that one infection had been taking what another spared. He recurred to Watt’s doctrine time after time in his annual reports, and in that of 1872 (p. 224), expressed his belief thus plainly: “The zymotic diseases replace each other; and when one is rooted out, it is apt to be replaced by others which ravage the human race indifferently whenever the conditions of healthy life are wanting. They have this property in common with weeds and other forms of life: as one species recedes, another advances.” Two remarks remain to be made under the doctrine of displacement. The first is that the substitution of measles for smallpox was one of a series of such changes in the public health of Britain. The great infective scourge of medieval and early modern periods had been plague, which destroyed at times immense numbers of the valuable or mature lives. Its successor was typhus fever, which also cut off the parents more than the children, but did not retard population as the plague had done. The saving of life by the extinction of plague was in great part balanced by the loss from smallpox, which fell, however, more and more upon the earliest years of life until at length it was almost confined to them. The first great decline of smallpox itself corresponded to a great decline of typhus fever during the second half of the French war; but while there was no great infectious disease in those years to thin the ranks of the adults, measles took the place of the more loathsome smallpox in cutting off a certain number of young lives. While the older types of infection have disappeared, the incidence has shifted from mature lives to children, so much so that at the present time enteric fever, and occasional choleras and influenzas, are almost the only infections that correspond to the old plague and to typhus fever in their age-incidence. The other remark is that the greater prevalence or fatality of measles, as if in lieu of smallpox, meant a good deal more for the bills of mortality than actually appeared under the name of measles. Smallpox was not an infection that did much constitutional damage to those that came through it, although it sometimes destroyed the vision and spoiled the beauty of the face. On the contrary, it was held by many that the general health was better after an attack of smallpox than before; and, if personal experience can justify an opinion, that ought to be my own view of the matter[1221]. But measles is an infection peculiarly apt to leave mischief behind. The bronchial catarrh, which is an integral part of the malady, and is often the cause of death in the second stage of the attack, may so affect weakly children that the respiratory organs are permanently damaged. Tuberculosis of the lungs is apt to follow measles. Some children, again, fall into mesenteric disease after measles, and die tabid, the intestinal catarrh being as dangerous in one way as the bronchial is in another. Another large proportion of the subjects of measles take whooping-cough[1222]. While smallpox did its work summarily, the full effects of measles were longer in being realized. This may in part explain the fact brought out by Watt, that while fewer children died under two years of age, measles being the dominant epidemic disease, there was an increase in the ratio of deaths from all causes between the years of two and five and from five to ten. Measles in the Period of Statistics. The history of measles for nearly a generation after the great epidemics of 1808 and 1811-12 is little known. No one in Glasgow continued Watt’s laborious tabulation of the causes of deaths in the numerous burial registers[1223]; nor was any regular account kept elsewhere except by the Parish Clerks of London. The following deaths by measles in their bills from 1813 to 1837, when the modern registration began, were probably no more than from a third to a half of the deaths in all London: Measles Year deaths 1813 550 1814 817 1815 711 1816 1106 1817 725 1818 728 1819 695 1820 720 1821 547 1822 712 1823 573 1824 966 1825 743 1826 774 1827 525 1828 736 1829 578 1830 479 1831 750 1832 675 1833 524 1834 528 1835 734 1836 404 1837 577 The inadequacy of these figures to the whole of London will appear from the fact that the registration returns under the new Act gave for the last six months of 1837 the measles deaths at 1354, while the bills of the Parish Clerks gave them at 577 for the whole year. But the old bills enable us to compare the deaths from different diseases within the same area and under the same system of collection, and to compare the deaths “within the bills” in a series of years since the last of the new parishes were taken in about the middle of the 18th century. Using the bills so far legitimately, we find that measles at length came to be of equal importance with smallpox itself as a cause of death in childhood, and that it had become a larger and steadier total from year to year. So far as concerns Glasgow, the high mortality from 1807 to 1812, making 10·76 on an annual average of the deaths from all causes, was not maintained. When the tabulation of the causes of death was resumed from 1835, the annual average of measles for the five years ending 1839 was found to be only 6 per cent. of the deaths from all causes, the average of smallpox having come back to 5·3 per cent. During that unwholesome period, in which there was much distress among the working class and a great epidemic of typhus, measles and smallpox were dividing the infectious mortality of childhood somewhat equally, the age-incidence of measles being only a little lower than that of smallpox: _Ages of the Fatal Cases of Measles in Glasgow, 1835-39_[1224]. Under one 1-2 2-5 5-10 10-20 20-30 30-40 40-50 Total 1835 116 141 121 34 10 4 - - 426 1836 86 209 183 38 1 1 - - 518 1837 77 133 122 16 2 1 350 1838 76 124 161 39 3 1 1 405 1839 165 259 275 73 7 2 1 783 -------------------------------------------------------- 520 866 863 200 23 9 1 1 2482 In Limerick, which may stand for a typically unhealthy Irish city in the worst period of over-population, there were many more deaths from smallpox among children than from measles, the age-incidence being nearly the same, according to the following dispensary statistics for a number of years before 1840[1225]: _Limerick Dispensary Deaths._ Age 0-5 5-10 10-15 15-20 Total Smallpox 333 55 5 0 393 Measles 187 32 6 1 226 Scarlatina 8 2 10 Although it is impossible to prove it, yet the indications all point to measles having kept for a whole generation after 1808 the leading place among infantile causes of death which it then for the first time definitely took[1226]. Almost the only direct references to the subject were made by way of controverting the doctrine of Watt; but these are too meagre, or too general in their terms, to be of any use[1227]. The epidemics of measles seem to have travelled then, as they do now, from county to county in successive years. Thus in 1818, while most parts of England were or had recently been suffering from smallpox, the Eastern counties were suffering from measles “very frequent and fatal.” Smallpox at length reached Norwich in 1819, and became the reigning epidemic in the place of measles, which was “hardly met with” so long as the enormous mortality of the other disease proceeded[1228]. At Exeter in the spring of 1824 measles became epidemic after a long interval; many susceptible children had accumulated, and of these few escaped. The mortality was very great, and was caused by severe pulmonary inflammation, the catarrhal symptoms being mild. In one day seventeen children were buried in one of the five parish churchyards of the city; but that high mortality, according to the parochial surgeon, did not on an average stand for more than four deaths in one hundred cases[1229]. When the curtain rises, in the summer of 1837, upon the prevalence and distribution of diseases in England, as ascertained by the new system of registration of the causes of death, measles is found in the first place among the infectious maladies of childhood, thereafter yielding its place to smallpox for a year or more, and taking the lead again until it was passed by scarlatina. _Deaths by Measles and Smallpox in London, 1837-39._ 1837 1838 1839 3rd Qr. 4th Qr. 1st Qr. 2nd Qr. 3rd Qr. 4th Qr. (four quarters) Measles 822 532 173 96 94 225 2036 Smallpox 257 506 753 1145 1061 858 634 The epidemic of smallpox hardly touched the Eastern counties until 1839; so that while the home counties in that year had far more deaths by measles than by smallpox, Norfolk had only 72 deaths by the former against 820 deaths by the latter. In the same year measles took the lead in four out of six great English towns, scarlatina being the dominant infection in one (Sheffield), and smallpox in one (Bradford): _Deaths in 1839 by the three chief infections of Childhood._ Liverpool Manchester Leeds Birmingham Sheffield Bradford Measles 401 773 383 170 33 70 Scarlatina 374 264 35 133 419 7 Smallpox 259 237 171 56 16 208 In all England and Wales during fully half-a-century of registration, measles has fluctuated somewhat from year to year but has not experienced a notable decline among the causes of infantile mortality (see the table at p. 614). In the decennial period 1871-80, its annual average death-rate was 377 per million living; in the next decennium it rose to 441, the previously high rates of scarlatina having fallen greatly. Among the highest rates for the ten years 1871-80, were those of Plymouth, 1·13 per 1000, East Stonehouse 1·79, and Devonport 1·19 (owing to a great epidemic in 1879-80), Exeter, 0·82, Liverpool ·91, Bedwelty (Tredegar and Aberystruth collieries) 0·88, Wigan 0·74, Whitehaven 0·71, Alverstoke 0·81. In the most recent period there have been some very high death-rates; thus at Jarrow the annual rate, which was only ·27 per 1000 from 1871 to 1880, rose in the nine years 1881 to 1889 to an annual average of ·94, having been made up almost wholly by great epidemics every other year--in 1883 (2·9), 1885 (2·4), 1887 (1·4), and 1889 (·9)[1230]. In the year 1888, an epidemic at Stoke-on-Trent, Hanley, &c. with 342 deaths, made a rate of 2·8 for the year; in Wolstanton, Burslem, &c., 221 deaths were equivalent to a rate of 2·6. The latest reports of the Registrar-General have traced a progression of the epidemic of measles from county to county or from district to district in successive years, such as was remarked, both for smallpox and measles, by some of the 18th century epidemiologists in England, Scotland and Ireland. Thus in 1890, measles was epidemic in Cheshire, South Lancashire and North Staffordshire; in 1891 it ceased in these, but became epidemic in North Lancashire, South Staffordshire and the West Riding; in 1892 it ceased in its last-mentioned area, and became epidemic in Warwickshire, Leicestershire, Derbyshire, the East and North Ridings, Westmoreland and Durham. During the same three years a similar progression or cycle was observable (on looking over the tables) in the South-west of England. The epidemic year of measles in Devonshire was 1889. It ceased there, and became epidemic in 1890 in Cornwall on the one side and in Somerset on the other, sparing Dorset. In 1891 it ceased to be epidemic in those parts of Cornwall and Somerset which it occupied in 1890, and became prevalent in the extreme west of Cornwall, in parts of Somerset, in Wiltshire and in Gloucestershire. In 1892 it ceased in all the last-mentioned excepting Gloucestershire, and became epidemic in Dorset, where there had been no severe prevalence of measles since 1888[1231]. Measles has no such decided preference for a season of the year as scarlatina and enteric fever have for autumn or infantile diarrhoea has for summer. But it often happens that most deaths are recorded from May to July, owing, doubtless, to the greater number of attacks in summer and not to any excessive fatality of that season. In London and the great industrial towns the deaths are spread somewhat uniformly over the year; or, in the language of statisticians, the maxima do not rise far above the mean of the year. In a tabulation of the weekly deaths in London from 1845 to 1874[1232], it appears that they touch a higher point in mid-winter (Nov.-Jan.) than in summer, a fact which may be readily accounted for by the injurious effects of the London air in winter upon a disease which is largely a trouble of the respiratory organs. In the great industrial populations of Lancashire, which resemble London in their high death-rate from measles, the rise of the deaths in mid-winter is almost the same as the summer increase[1233]. Most of the deaths from measles fall at present upon the ages from six months to three years, just as they did when the deaths were comparatively few, as at Manchester from 1768 to 1774. Deaths of adults, which were not altogether rare in the first great epidemic of modern times in 1808, are seldom heard of at present, for the same reason that adult deaths used to be uncommon in smallpox, namely, that the disease is passed by almost everyone in infancy or childhood. Although the deaths from measles sometimes reach large totals--in London during the spring of 1894 they were in some weeks as high as one hundred and fifty--yet it is the common experience of practitioners that a strong or healthy child rarely dies of measles, that the fatalities occur among the infants of weakly constitution, and especially in the numerous families of the working class in the most populous centres of mining, manufactures and shipping. To bring these various characteristics of measles together in a concrete instance, I shall give briefly the facts of a recent epidemic in a town in Scotland of some twelve thousand inhabitants. There had been only five deaths from measles for two years. There had not been a case of smallpox for at least ten years. The measles epidemic, when its triennial opportunity came, reached a height in July, on a certain day of which month there were seven or eight burials from measles or its direct sequelae. Nearly all the children in the place who had not been through the measles in the corresponding epidemics of 1889 or 1887 suffered from it on this occasion, excepting the class of very young infants. The deaths in the whole epidemic numbered about fifty, which would not all be registered, however, as from measles. Yet this high mortality was not due to any unusual malignancy of the disease, but to the feeble stamina of a certain number of infants, or to the indifferent housing and tending of the poorer class. One did not hear of a death in the well-to-do families (probably there was none), although they had their full share of attacks. The frequency of the burials for a short time, and the effects of the epidemic on the mortality from first to last, must have been very nearly the same as in an epidemic of smallpox a century before, when the population was only a third or fourth part as large. But in the period when smallpox was in the ascendant, having few rivals among the infective causes of death in childhood, the general conditions of health in this town were altogether different. One or two specimens of the thatched huts of the poorer class had been left standing into the era of photography, so that we could compare past with present, in externals at least; also, of the houses of the richer class some still remained, perhaps turned into tenement-houses, with small windows, low doorways, and crow steps on their gables; and it was on record by the parish minister at the end of the 18th century, that within the memory of that generation there had been peat stacks and dunghills before the doors on the High Street of the burgh.