introduction into the system;” and this he had been doing in the name of

Jenner, under the influence of a belief that, if cowpox were not smallpox, it ought to be, that it was a pity the disease had ever been called cowpox, and that the name (which was a very old one) “has only served to debase it in the eyes of the common people, and prevent its general adoption[1129].” The very director of the Jennerian institute was among the prophets of the old inoculation. With the revival of smallpox in general epidemic diffusion in 1816-19 we begin to hear more of the old inoculation. The account already cited of the outbreak at Ulverston contains a table of fourteen previously cowpoxed children whom it was thought desirable during the epidemic to inoculate with smallpox, all of them receiving the infection in one degree or another. A practitioner at Dunse, Berwickshire, not only returned to the old inoculation (thereby incurring “much odium,” as he believed), but actually took his matter from the natural smallpox of his cowpox failures[1130]. When the epidemic reached the Eastern Counties, there were demands for the old kind of inoculation, not in Norwich only, but in numerous country parishes. Of ninety-one surgeons in Norfolk and Suffolk, who answered the queries of Cross, thirty-eight had practised the inoculation of smallpox in the epidemic of 1819; five of them, after having refused many private applications for inoculation in the old way, had at length yielded to the desire of the Overseers of the Poor, and had inoculated whole parishes. Cross’s correspondents also testified that there was much inoculation going on at that time in the Eastern Counties by the hands of farriers, blacksmiths, tailors, shoemakers and women. Dr John Forbes, who then practised at Chichester, brought to light an exactly similar state of public feeling in Sussex in 1821-22[1131]. In the parish of Bosham there lived a farmer named Pearce who had an inherited skill in inoculating, his father having inserted smallpox into ten thousand persons in his day, without killing one of them. Pearce offered to wager with Forbes a considerable sum that he would inoculate any number of persons and that none of them should have more than twenty pustules. He believed that the smallpox matter became “as weak as water” by an uninterrupted transmission from one body to another. In November, 1821, the Overseers of the Poor employed him to inoculate the pauper children, and his skill was soon in request for others, so that from two to three hundred in the parish were inoculated by him within a short time. He charged half-a-crown or a crown for each. From other parishes the people flocked to him in such numbers that he inoculated upwards of a thousand in the winter and spring of 1821-22. Before long he had three itinerant rivals, a knifegrinder, a tinsmith and a fishmonger, who claimed to have inoculated together a thousand persons, including four hundred previously cowpoxed. The surgeons of Emsworthy and Havant at length joined in the business, and in the space of six or eight weeks inoculated from twelve to thirteen hundred persons, who had not been previously vaccinated. Forbes also received from his medical friends in and around Chichester “an account of 680 cases of previously vaccinated individuals subjected by them to variolous inoculation.” In the great majority of these the constitutional symptoms were so slight as to be only just observable, the eruption consisting of only a few pustules, which were all that the Pearces, of Bosham, father and son, ever expected to get with inoculated smallpox where no infection of cowpox had preceded. Disappointments with the new inoculation had led to a great revival of the old also at Canterbury, the operators being mostly women. The same thing happened in Cambridgeshire and in Bucks. In a parish within eleven miles of Cambridge several hundred persons were inoculated with smallpox in 1824, and in April, 1825, a medical practitioner inoculated a number in a village near[1132]. During a severe epidemic in the parish of Great Missenden, Bucks, which followed a general vaccination, and caused a prejudice against the latter, the old inoculation was generally resorted to[1133]. It looked for a brief period, about the time of the epidemic of 1824-26, as if the old inoculation were to return to favour even with the profession itself. Dr John Forbes wrote of the two kinds of inoculation in a studiously impartial manner. Dr Robert Ferguson, who was also destined to make a name, addressed in 1825 a letter to Sir Henry Halford in which he advocated a singular compromise, namely, two inoculations, one with cowpox, the other with smallpox, the cowpox to neutralize the contagiousness of the smallpox for the occasion, while the latter was to be the prophylactic against itself for the future[1134]. This reaction, if it deserves that name, corresponds in time to the great decline in the number of gratuitous vaccinations at Manchester, a decline which had been equally remarkable at Glasgow for some years before. There was at least an apathetic spirit towards cowpox inoculation during the epidemic of 1817-19, and for a good many years after it, while there was something like toleration, even among medical men, for the old inoculation. The Smallpox Epidemic of 1825-26. Compared with the epidemic of 1837-40, which was the first in England to be recorded under the new system of registration of the causes of death, the smallpox of 1825-26 makes a poor figure in the records. Yet there is reason to believe that it was an epidemic of the same general kind, if not of the same duration or fatality. At the Newcastle Dispensary far more children in the smallpox were visited in 1825 than in any year since its opening in 1777, namely, 113 cases, with 28 deaths, which would have been a small fraction of all the cases in Newcastle. At the Rusholme Road Cemetery, Manchester, which received about a fourth part of the burials, 112 children, all under seven years, were buried from smallpox in the six months, 18 June to 18 December, 1826[1135]. At Bury St Edmunds smallpox began to be epidemic about the end of 1824, when the guardians ordered a general vaccination, and reached its worst in July, 1825, the type being confluent in many of the cases[1136]. It was in Cambridgeshire villages the same year, and is casually heard of in Bucks[1137]. It had been severe at Oxford and Canterbury in 1824. At Glasgow the prevalence of fever is known for the corresponding years, but the smallpox deaths have not been taken out of the burial registers. The evidence from London is perhaps the best indication that the smallpox of 1825 was one of the more severe periodic visitations. The extensive prevalence of smallpox was heard of in Paris before the epidemic attracted much notice in London; the news of persons of distinction dying by smallpox in the French capital reads like the old notices of it in 17th century letters. In the same year it was very severe also in Sweden after a long period of quiescence. As to London, Dr George Gregory, physician to the Smallpox Hospital, said[1138]: “It may be inferred that smallpox has been nearly as general in 1825 as in any of the three great epidemics of the preceding century”--the demand for admission to the Hospital being, in his opinion, a fair index; while private information confirmed the estimate of its truly epidemic prevalence, and of its incidence chiefly upon the lower classes[1139]. In the years of the 18th century to which he referred, and in four maximum years of the 19th century, the cases and deaths at the Smallpox Hospital had been as follows[1140]: _London Smallpox Hospital._ Year Cases Deaths 1777 497 125 1781 646 257 1796 447 148 1805 280 97 1819 193 61 1822 194 57 1825 419 120 While the demands upon the beds of the hospital pointed, as Gregory supposed, to the existence of a great epidemic in London, comparable to those of 1777, 1781 or 1796, in which years the smallpox deaths were returned by the parish clerks at 2567, 3500 and 3548 respectively, yet in 1825 the bills showed only 1299 deaths from smallpox. Gregory accepted without demur the figures of the parish clerks’ bills in 1825, although it is well known that they had become more and more defective, even for the original parishes, since the end of the 18th century[1141]. “But for the general prevalence of vaccination,” he said, the smallpox deaths in 1825 would have been 4000 in the same number of attacks, the difference being in the rate of fatality. His conclusion for all London was based upon the experience of the Smallpox Hospital. The patients received by that charity were of the same class as formerly, most of them being adults, among whom the proportion of fatalities was greater than at all ages. Taking the three epidemics of the 18th century with which he compared the epidemic of 1825 in respect of extent or number of attacks, we find that 25 per cent. of the cases admitted died in 1777, 39 per cent. in 1781 (the seasons were unwholesome by epidemic agues, dysenteries, and typhus), and 33 per cent. in 1796. The average of fatalities at the hospital from its opening in 1746 to the end of the century was about 29 per cent., and that was exactly the ratio of deaths among the 419 patients in 1825. The rate of fatality was a little higher than in the epidemic of 1777, and a little lower than in each of the epidemics of 1781 and 1796. Gregory in 1825 was enabled to separate the sheep from the goats by the dividing line of cowpox, the former dying at the rate of 8 per cent., the latter at the rate of 41 per cent. There are various ways of apportioning a general average. The presence or absence of cowpox scars is one principle, which could not have been used to break up the 25 per cent of 1777, or the 39 per cent, of 1781, or the 33 per cent. of 1796, into two component parts. One thing common to all times is the different rate of fatality at different ages. All the deaths in the 8 per cent. division of 1825 were between the ages of eighteen and twenty-seven; the ages of the 41 per cent. division are written in the books of the hospital. In portioning out the general rate of fatality from typhus fever at the London Fever Hospital, it is found that the dividing line of age is nearly the same as the dividing line of social position; in one table the high ratio of deaths to attacks is among persons in the second half of life, and the low ratio among persons in the flower of their age; in another table the many deaths to cases are among paupers, and the few fatalities among paying patients[1142]. However manifold the cutting up of a general average, some divisions would be identical, corresponding to natural lines of cleavage. Having indicated the chief points in the vaccination controversy by the instance of Gregory’s arguments sixty years since, (to which might have been added the question of efficient or inefficient vaccination according to the appearance of the scars in after life[1143]), I shall for the rest depart from the usual practice of interlocking the history of smallpox epidemics with the history of vaccination. I shall treat the latter as _ex hypothesi_ irrelevant, leaving it to each reader to incorporate, as matter of his own familiar knowledge or belief, whatever effects of cowpox upon smallpox, whether temporary effects or permanent, modifying effects or absolutely prophylactic, may suit his particular creed. I am led to take this course for several reasons. It leaves me free to look at the epidemics of smallpox from the same point of view as the other epidemics treated of in this work. It avoids a controversy which, unlike that of inoculation, is still actual, and unsuited to a historical treatise. It enables me to omit the excuses for failure, which are apt to be interminable and to usurp the whole space available for the epidemiology proper. Lastly, the irrelevancy which I here conveniently assume happens to be my real belief,--as elsewhere set forth in an examination of the antecedent probability arising out of the pathological nature and affinities of cowpox, and in a study of the grounds on which the authority of the profession was originally given to Dr Jenner’s teaching. The interval between the epidemic of 1825 and that of 1837-39 was occupied by a good deal of smallpox steadily from year to year in London, the deaths from which, in the following table from the bills of mortality, are to be understood as only a part of the whole, according to the explanation already given: Smallpox Year deaths 1826 503 1827 616 1828 598 1829 736 1830 627 1831 563 1832 771 1833 574 1834 334 1835 863 1836 536 1837 217 The inadequacy of these returns will appear from the fact that the 217 deaths in 1837 rose, under the new system of registration, from 1 July to 31 December, to 762, or to fully three times as many for the last six months as the parish clerks returned for the whole year. Their bills had become most defective when they were about to be, or had been superseded; but even on the special occasion of the cholera in 1832 they returned only some three-fifths of the known deaths. Besides these London figures there is little to show the extent of smallpox in England between the epidemic of 1825 and that of 1837-39. This was the time when many complaints were made of the so-called loss of power or strength in the current cowpox matter for inoculation. These complaints appear to have arisen from the greater frequency of smallpox among the cowpoxed, corresponding to the increasing numbers of the whole population who had received that kind of inoculation. “Secondary smallpox,” says a report from Worcestershire in 1833, “has been very prevalent of late years[1144],” the term “secondary” reflecting the teaching of Baron, chairman of the Smallpox Committee of the Medical Association, that cowpox itself was the primary smallpox. The increasing number of the vaccinated who took smallpox was clearly shown in the returns from the Smallpox Hospital of London, and was believed to be in proportion to the increasing number of the rising generation who had been vaccinated[1145]. A generation of Smallpox in Glasgow. Glasgow had afforded the most striking instance in Britain of the decline of smallpox after the beginning of the 19th century. The decline was observed everywhere, but it was most noticeable in Glasgow, partly because the smallpox mortality of infants at the end of the 18th century had been excessive there, partly because Dr Watt took the trouble to prove it statistically from the burial registers. In the last six years of the 18th century, 1795-1800, smallpox had contributed 18·7 per cent. of the deaths from all causes; from 1801 to 1806, it contributed 8·9 per cent., and from 1807 to 1812 only 3·9 per cent. In the next six years, 1813-19, if Cleland’s search of the registers has been as laborious as Watt’s, the share of smallpox was only 1·07 per cent. of the deaths from all causes, which would mean that Glasgow was hardly at all touched by the epidemic of 1817-19, reported from many other parts of Scotland[1146]. But the lull in smallpox, which corresponded on the whole to the still greater lull in fevers during the prosperous times of the second half of the French war, was broken in Glasgow, if not in 1817, yet before long. Unfortunately there is a break in the statistics also. From 1821 the magistrates caused annual bills of mortality to be published, which did not, however, specify the causes of death until 1835[1147]. But we have some intermediate glimpses of the state of the poorer classes and of the prevalence of smallpox in particular. Writing in 1827, Dr Mac Farlane one of the poor’s surgeons, remarks upon the feeble stamina, sallow complexions, and the like, of all but a few children in the more crowded parts, adding that smallpox both in the virulent and “modified” forms had been more prevalent during the last three or four years than formerly[1148]. Three years after, Drs Andrew Buchanan and Weir gave an account of the state of the poor in Glasgow, which shows that it had actually deteriorated with the growth of the city. The poorer classes had been in some part displaced from their old dwellings in the heart of the town owing to the building of warehouses or the like, and had been provided with no new habitations as good as the old. “Apartments originally intended for cellars, and occupied as such until lately, are now inhabited by large families, and the only opening for light and air is the door, which when shut encloses the poor creatures in a tainted atmosphere and in total darkness. This is well exemplified in the cellars belonging to the houses on the south side of St Andrew’s Street.” Not only the notorious region of the Wynds, containing part of the three parishes of the Tron, St Enoch’s and St James’s, but also the Saltmarket and Gallowgate, were crowded with a destitute, vagrant and often vicious class of people. Many of the houses in the Wynds, with their network of alleys, were only one or two storeys high, in the old Scotch fashion; here were the night lodging-houses, with several beds in one room, two or three persons in a bed, twelve to eighteen people in as many square feet: “the extreme misery of these poor people is utterly inconceivable but to those who have actually witnessed it; it has certainly been carried to the very utmost point at which the existence of human beings is capable of being maintained. Some of them are lodged in places where no man of ordinary humanity would put a cow or a horse, and where those animals would not long remain with impunity.” Buchanan found sometimes a horse, sometimes an ass, sometimes pigs, in the same dungeon with one or more families[1149]. Such was the region in which Chalmers ministered from 1815 to 1822, first in the Tron parish, afterwards in the poor and crowded parish of St John’s. Things got no better, certainly, after he left worn out by his exertions, to become professor at St Andrews. Buchanan thought the best index of the degradation of the people in 1830 to be that not one in ten ever entered a church (if they had, he explains, the respectable congregation would have fled from their filth and rags). “The people are starving,” he exclaims, “and there is a law against the importation of food[1150].” It took sixteen years longer to secure the benefits of free trade, and meanwhile the public health of Glasgow got worse rather than better. The infantile part of it attracted far less notice than that which touched adults, so that we hear little of smallpox, while the records of fever and cholera are fairly complete. When the curtain is lifted in 1835 by the publication of statistics, the mortality of infants and children by infectious diseases is found to be proceeding as follows: _Glasgow Mortalities, 1835-39._ Deaths Deaths Deaths Deaths from all from from from Year causes smallpox measles scarlatina 1835 7198 473 426 273 1836 8441 577 518 355 1837 10270 351 350 79 1838 6932 388 405 87 1839 7525 406 783 262 According to the following table of the ages at death from smallpox, it will appear that a higher ratio of infants died of it in their first year at Glasgow than was the rule elsewhere, whether in the 18th or in the 19th century. It was only in the year 1837, when typhus was at its worst and smallpox had somewhat declined, that the deaths by the latter of infants under one year were fewer than those of infants in their second year: _Glasgow: Table of Deaths from Smallpox 1835 to 1839._ Under Above 1 1-2 2-5 5-10 10-20 20-30 30-40 40 Total 1835 204 154 75 17 14 8 1 0 473 1836 202 174 144 23 6 24 2 2 577 1837 93 116 94 24 10 11 4 0 352 1838 111 99 119 28 11 14 4 2 388 1839 137 98 113 19 15 17 5 2 406 Totals of five years 747 641 545 111 56 74 16 6 2196 \---------v---------/ Percentages 34% 29% 25% 5% 7% Cowan, who published these figures in 1840, had written eight years before, “I fear that if the list of infantile diseases were still published in the mortality bills many deaths from smallpox would annually be found.” We do, indeed, hear of epidemics of smallpox not far from Glasgow. At Stranraer, in Sept.-Nov. 1829, “measles and smallpox attacked with scarcely an exception” all the children in the place who had not acquired immunity either by previous attacks or by the influence of vaccination; “and even these powerful protectives were, in many instances, of no avail.” The subjects of “unmodified” smallpox were nearly all infants of the poorer class. In St John’s Street, occupied by decent Scots labouring people, ten children had “unmodified” smallpox and all recovered; in Little Dublin Street, so called from its Irish tenants, fourteen children had smallpox, of whom six died[1151]. At Ayr, about the same time, there was an epidemic, which came to a height in 1830, causing a considerable mortality[1152]. At Edinburgh in the winter of 1830-31, it was unusually prevalent and fatal, the epidemic dying out in May, 1831[1153]. For three or four years, 1843-46, there was another lull in the prevalence of smallpox in Glasgow; but the mortality rose again, reaching in the two years 1851 and 1852 the total of 1202, in a population of 360,138, which contrasted with the 2212 deaths in London in the same two years, and with the Paris mortality of 706 in the two years 1850 and 1851, in a population of about one million, the deaths being still almost wholly infantile in Glasgow while they were in great part of adults in Paris[1154]. _Glasgow Smallpox._ Smallpox Year deaths 1840 455 1841 (pop. 282,134) 347 1842 334 1843 151 1844 99 1845 195 1846 not recorded 1847 592 1848 300 1849 366 1850 456 1851 (pop. 360,138) 618 1852 584 Registration of the causes of death began in Scotland in 1855. In the first decennial period, to 1864, the smallpox deaths were 10,548, falling upon infancy and other age-periods as in the following table[1155]: Age-periods Smallpox deaths Under three months 774 Three to six months 668 Six to twelve months 1543 One to two years 1765 Two to three years 1132 Three to four years 798 Four to five years 514 ---------------------------------- Total under five years 7194 Above five years 3354 ------ 10,548 Smallpox in Ireland, 1830-40. Before coming to the epidemic in England let us glance at the prevalence of smallpox at this period in Ireland. Dr Cowan, of Glasgow, was struck by the fact that among ninety patients in the Infirmary with smallpox, all adults, only four were from the considerable Irish population of the city, the larger number being natives of the Highlands of Scotland. This leads him to say: “The immunity of the Irish from smallpox is owing to the general practice of vaccination among the lower classes by the surgeons of the county and other dispensaries” (another Glasgow writer ascribes the prevalence of smallpox to the Irish negligence in the same matter). It happens that we can bring one part of this statement to a statistical test. The same volume of the _Journal of the Statistical Society_ which contained the paper on the vital statistics of Glasgow contained also a statistical account of the public health of Limerick, by Dr Daniel Griffin, physician to the Dispensary[1156]. Dr Griffin’s figures were of the only kind that could then be got for an Irish town, and were representative rather than exhaustive. Struck by the seemingly enormous death-rate of infants in the poorest quarters of Limerick, he sought to bring out the facts with numerical precision. He provided a register-book at the Dispensary, in which he entered the results of his observations and retrospective inquiries among eight hundred families of the poorest class during “a good many years” down to 1840. The city of Limerick, and especially the parish of St Mary, was full of the misery and destitution that characterized Ireland in the years of its greatest over-population. The ejected cottiers and broken small farmers of the neighbouring county flocked to it, living in beggary in wretched lodging-houses with swarms of infants and children, the breadwinners finding only an occasional day’s work as labourers. Among 800 such families during the years of his inquiries the chief causes of death among the infants and children were as follows: _Limerick Dispensary Deaths._ Under Five Five to Above years Ten Ten Total Convulsions 569 18 7 594 Smallpox 333 55 5 393 Measles 187 32 7 226 Diarrhoea and Dysentery 108 19 24 151 Whooping cough 84 10 1 95 Croup 85 9 1 95 Scarlatina 8 2 0 10 Fever 70 33 66 169 The more exact ages at death from smallpox in male and female children were: Under One and Three and Five to Above One Two Four Nine Nine Males 33 72 37 29 2 Females 52 92 47 26 3 -- --- -- -- -- 85 164 84 55 5 As compared with Glasgow, measles at Limerick has a much lower place than smallpox in the infantile mortality, while scarlatina hardly counts at all. Again, only 1·27 per cent. of the smallpox deaths are above the age of nine, whereas at Glasgow 7 per cent. are above the age of ten. Griffin’s data for reckoning the probability of life were incomplete, as he was well aware; so that the following comparison of the poor attending Limerick Dispensary with all England and Wales probably errs in making the Irish town somewhat more fatal to infants of the poor than it really was: England and Wales Limerick Dispensary in 1000 deaths in 1000 deaths Under one year 214·54 327·71 One and under three 128·00 287·67 Three and under five 48·51 128·20 Five and under ten 46·07 97·29 Ten and under fifteen 25·91 24·93 Fifteen and under twenty 34·16 20·37 In a thousand deaths at all ages, 391·05 occurred before the age of five years in England and Wales, but 743·58 before the age of five years among a certain section of the poor of Limerick; and in the latter enormous sacrifice of infant life smallpox was the greatest single means next to convulsions. Perhaps that was the reason why so few of the Irish in Glasgow were attacked by smallpox in adult age. The experience of Limerick was not exceptional in Ireland. In the ten years 1831-40, for which the causes of death were ascertained by means of queries in the census returns of 1841, the total of deaths by smallpox was 58,006, nearly double the mortality by measles (30,735) and seven times that of scarlatina (7,886). It was almost wholly a malady of infants and children, the first and second years of life being its most fatal period. Only 129 of these deaths were returned from hospitals. The bulk of the decennial smallpox deaths fell in the two years 1837 and 1838, corresponding with the high epidemic mortality in England[1157]. The Epidemic of 1837-40 in England. The smallpox epidemic of 1837-40 was already in full force at Liverpool, Bath and Exeter when the mortality returns began to be made on 1st July, 1837, under the new Registration Act. Whether or not the contagion travelled from Ireland or the west of Scotland, the epidemic in England began in the west and south-west, and reached the Eastern counties last. The following table shows its rise and progress at selected places in the several quarters, beginning with the third quarter (July-September) of 1837[1158]: 1837 1838 1839 +---------+ +---------------------+ +---------------------+ 3rd 4th 1st 2nd 3rd 4th 1st 2nd 3rd 4th qr qr qr qr qr qr qr qr qr qr Liverpool 375 132 32 24 18 36 11 29 75 138 Bath 154 18 15 1 1 2 1 25 17 30 Exeter 88 131 6 -- 2 -- -- -- -- -- Bristol 21 74 72 44 4 7 6 -- -- -- Clifton 16 32 49 27 7 -- -- -- 1 7 London 257 506 753 1145 1061 858 364 117 65 60 Manchester 23 98 127 120 111 180 94 40 33 53 Birmingham 34 55 85 86 66 47 26 12 7 10 Sheffield 14 14 27 36 22 12 9 3 4 -- Leeds 4 11 29 69 134 197 74 55 30 15 Newcastle 16 17 66 11 -- 23 54 24 39 25 Abergavenny and 13 85 102 50 22 21 22 30 26 10 Pontypool Merthyr Tydvil 9 54 160 91 10 3 18 16 12 -- Weymouth, Bridport, and 4 19 92 31 8 4 10 9 2 -- Beaminster Plymouth 10 15 11 14 37 48 9 8 1 -- Taunton -- 7 66 40 4 3 -- -- -- -- Leicester 43 5 3 2 3 3 9 21 5 15 Norwich 1 -- -- -- -- 17 180 204 10 7 Lynn etc. -- 1 2 10 7 4 127 81 6 -- Ipswich -- -- 2 6 38 95 23 -- 1 -- Bury St Edmunds 1 3 30 24 2 3 -- -- -- -- etc. Woodbridge etc. 4 9 27 16 5 11 10 2 -- 4 The epidemic having begun in the west and south-west in the summer of 1837, spread in the winter of 1837-38, all through the hills and valleys of Wales, causing high mortalities around Abergavenny, Pontypool, Merthyr Tydvil and other towns in the first quarter of 1838, as well as in the rural parishes. It was not until the end of 1838 that the contagion spread widely over the Eastern counties. The epidemic in Norwich was again short and sharp, like that of 1819, most of the 418 deaths falling within six months of winter and spring, just as most of the 530 deaths in 1819 fell within six months of summer and autumn. The population in 1821 was 50,288, and in 1841, 62,344; the increase was only 1228 between 1831 and 1841, so that the smallpox of 1839 fell upon a stationary population, whereas that of 1819 had fallen upon a rapidly increasing one. In the autumn of 1839 and throughout 1840, a second outburst of smallpox took place in the towns where the epidemic had started two years before, namely, Liverpool, Bath, Bristol, Clifton, etc[1159]. But the smallpox of 1840, which produced more deaths than that of 1839, was mostly centred in the Lancashire manufacturing towns, where also the mortality from scarlet fever was enormous. The circumstances of the working class in Lancashire at this time have been described in the chapter on fevers. The following shows the large proportion of smallpox deaths that fell in 1840 to the North-Western or Lancashire registration division. _Smallpox Deaths, 1840._ 1st qr 2nd qr 3rd qr 4th qr England and Wales 2071 2476 2274 3613 ------------------------------------------------------------ Of which in the N.-W. Division (Lancashire) 1046 986 533 590 The epidemic continued in the manufacturing towns into 1841; in the more rural registration divisions of England it had almost ceased in 1839. From the 1st July, 1837 (beginning of registration) until the 31st December, 1840, the epidemic smallpox in England and Wales caused 41,644 deaths. In 1838 it eclipsed both measles and scarlatina as a cause of death among children; but in 1840 scarlatina gained the leading place and kept it. Legislation for Smallpox after the Epidemic of 1837-40. The epidemic of smallpox in 1837-40, which was fatal chiefly to infants and young children, was one of the greatest, like the corresponding epidemic of typhus among adults, in the whole history of England. The troubles of the working class had been more or less chronic ever since the booming times of the Peninsular War had come to an end; the climax was reached in the thirties; the enormous sums spent upon railway construction gave a relief in the forties; and the permanent cheapening of food by Free Trade made an entirely new era, which became visible in the public health after the contagion of the Irish famine had ceased in 1848. The great and hitherto permanent decrease of typhus was brought about by social and economic causes. There, at least, _laissez faire_ was all powerful: “Let us be saved,” said Burke, “from too much wisdom of our own, and we shall do tolerably well.” But there has been at no time since the 18th century the same passiveness towards smallpox; that is a disease against which we must always be doing something direct and pointed. The legislation against smallpox began in England (nothing was done for Ireland and Scotland until long after) with the Act of 1840. It is a singular instance of the changes in medical opinion and of the vicissitudes of things that the first statute against smallpox should have been instigated by a desire to suppress the old inoculation. Parliament was first moved to action by the Medical Society of London through a petition presented by Lord Lansdowne; but things had been moving that way for some time before in the councils of the British (then the Provincial) Medical Association, under the influence of Dr Baron, the executor and biographer of Dr Edward Jenner. The Bill of 1840 was brought into the House of Lords by the second Lord Ellenborough, and conducted through the Commons by Sir James Graham, who was not then in office. It purposed to enable the poorer classes to get their children vaccinated, if they so desired, at the cost of the ratepayers, and to prohibit under penalties the practice of the old inoculation by amateurs or empirics. Blomfield, bishop of London, said in the Lords’ debate that many of the ignorant poor, in agricultural districts, were strongly prejudiced against inoculation with cowpox, and that they paid much greater attention to empirics, meaning inoculators by the old method, than to the advice of the clergy. In the Commons, Mr Wakley, who was a Radical and the proprietor of one of the weekly medical journals, declared that “no one could be ignorant that the working classes entertained great prejudices against vaccination,” although he did not explain why they were prejudiced. According to this medical authority, whom the House took seriously on that subject if on no other, the epidemic of smallpox which the country had just passed through had been in effect due to the contagiousness of the smallpox matter used in inoculating; and he succeeded in carrying an amendment to put down the old practice, not only in the hands of amateurs but also in those of medical men. The eighth clause of the Act decreed that any person convicted before two justices in Quarter Sessions of having wilfully procured the smallpox by inoculation shall be liable to a penalty of imprisonment for a term not exceeding one calendar month. The penal clause against the original inoculation was an indirect compliment to its vitality. Lord Lansdowne also paid it a compliment by recognizing the correctness of its principle; the rival inoculation-matter of cowpox, he said, was “perfectly identical” with smallpox, “although the symptoms were different.” This will be a convenient point in the history at which to review the rise and progress of the idea that the inoculation of smallpox was a wilful spreading of contagion and therefore a public nuisance. The risk of spreading the contagion of smallpox by inoculating the disease was one of the objections to the practice raised by Wagstaffe in his letter to Dr Freind in 1722: “I have considered,” he says, “how destructive it may prove to spread a distemper that is contagious.” Still more explicit was Dr Douglass of Boston, New England, writing on 1 May, 1722: “I oppose this novel and dubious practice ... in that I reckon it a sin against society to propagate infection by this means, and bring on my neighbour a distemper which might prove fatal, and which, perhaps, he might escape (as many have done) in the ordinary way.... However, many of our clergy have got into it, and they scorn to retract[1160].” Within a few months there was a striking instance of the alleged danger in one of Maitland’s inoculations at Hertford, an inoculated child, with only twenty pustules, having been supposed the probable source of the natural smallpox in five domestics, of whom one died. The death of the Duchess of Bedford by the natural smallpox in 1724 happened “after two of her children were recovered of that distemper, which they both had by inoculation[1161].” That risk, however, was little made of in the controversy, although it may have been one of the tacit reasons that led to the total abandonment of inoculation during the ten or twelve years after 1728. On the revival of the practice after 1740, when the serjeant-surgeons, the physicians and the apothecaries were all making it a considerable part of their business among the richer classes, the danger from contagion was either non-existent or it was not realized. In 1754 the College of Physicians of London, by a formal minute, recommended inoculation as “highly salutary to the human race,” without one word of warning on the risk of contagiousness. That objection was raised again when Sutton’s practice in 1765-67 was drawing large crowds to be inoculated. He was put on his trial at the Chelmsford Summer Assizes in 1766 on a charge of spreading the contagion of smallpox, which was epidemic in the town; but the grand jury, charged by Lord Mansfield, threw out the bill. Sutton’s defence was to have been that he never brought into Chelmsford a patient capable of spreading the smallpox, that is to say, an inoculated person with smallpox enough on him to spread contagion[1162]. Shortly after came the controversy between Lettsom and Dimsdale as to inoculation of infants at their homes, which turned upon the risk of increasing the natural smallpox by a constant succession of artificial cases. Lettsom’s position was the same as Sutton’s, that the quantity of smallpox matter (he might have said the quality also) produced by inoculation was not sufficient to create an appreciable risk. As to the matter of fact, the quantity was indeed small: Sir William Watson declared that a single limb of an adult person in a moderate attack of the natural smallpox had as many pustules on it as all the seventy-four children, in one of his inoculations at the Foundling Hospital, had on their whole bodies. In the theory of contagion, an infinitesimal quantity is sufficient; but in reality it appears that contagion must be in excess to be effective, just as, in the nearest physiological analogy, fertilization seems to depend upon the copiousness of the pollen or seminal particles[1163]. The opposition to Lettsom’s project of general inoculations among the infants of the working classes in cities shows that the risk of contagion was made to serve at least an argumentative purpose. As to experience, Lettsom in 1778 declared that he knew no instance of contagion from that source during two years of inoculations among the poor of London[1164]. One writer of the time (1781) appealed boldly to the experience of sixty years: “Upon the first introduction of inoculation, physicians, divines, and innumerable other writers [who were they?] cried out that the infection would be spread, and the community suffer a greater loss; but after sixty years’ experience, we should expect those arguments, as well as the writers, had all died away, and that at this day the same stale dregs of ignorance and obstinacy would not be again retailed[1165].” The risk, however, was not altogether imaginary. Some cases of smallpox caught from the inoculated were known. In Vienna at that time the rule was to allow no inoculations except on groups of subjects isolated for the purpose. When Jenner, in 1798, enumerated the advantages of cowpox over smallpox for inoculation, in certain specified circumstances, one of his points was its non-contagiousness[1166]. The favourable reception of his project seems to have been determined more upon that point than upon any other. The theoretical risk of contagion from inoculated smallpox became at once an actual danger to the community when it was perceived that they had in “smallpox of the cow” a non-contagious variety. Jenner was not slow to use that growing sentiment so as to discredit the old practice. As early as 1802 he began to urge privately the statutory prohibition of smallpox for inoculation, and Wilberforce, among others, took the matter up publicly. The College of Physicians, having been asked by Parliament in 1807 to inquire into the causes that hindered the progress of Jenner’s inoculation, inserted the following paragraph in their report: “Till vaccination becomes general, it will be impossible to prevent the constant recurrence of the natural smallpox by means of those who are inoculated, except it should appear proper to the Legislature to adopt, in its wisdom, some measure by which those who still, from terror or prejudice, prefer the smallpox to the vaccine disease, may in thus consulting the gratification of their own feelings, be prevented from doing mischief to their neighbours[1167].” The same year, in the court of King’s Bench, a medical practitioner was sentenced to fine and imprisonment for having neglected to prevent an inoculated person from communicating with others[1168]. Next year, 1808, a bill was brought into the House of Commons by Mr Fuller, with the following preamble: “Whereas the inoculation of persons for the disorder called the Smallpox, according to the old or Suttonian method, cannot be practised without the utmost danger of communicating and diffusing the infection, and thereby endangering, in a great degree, the lives of his Majesty’s subjects.”... This bill, which had clauses also for notification and compulsory isolation of smallpox cases, the churchwardens to be the authority, was not persevered with. The inoculators by the old method opposed it, and they were joined by Joseph Adams, who had been the first English writer to mention cowpox, in 1795, and had been a staunch vaccinist subsequently[1169]. In 1813 another attempt was made to restrict the practice of inoculating the smallpox on the ground of danger from its contagion, and to get cowpox substituted for it among the poorer classes. The Vaccine Board were the promoters, Lord Boringdon (afterwards Earl of Morley) having charge of the bill in the House of Lords. It was successfully opposed by the Lord Chancellor (Eldon) and by the Lord Chief Justice (Ellenborough), the latter contending that the common law was a better remedy than a statute against the nuisance of contagion from inoculated smallpox. Next year, 1814, Lord Boringdon brought in a new bill, which did not directly harass the inoculation interest, but made the rival method of cowpox obligatory upon the poor. Its provisions were ridiculed by Lord Stanhope, who got help from Lords Mulgrave and Redesdale to throw it out. Therewith ceased for many years the talk about the contagiousness of inoculated smallpox, together with the attempts in Parliament to enforce the rival inoculation. The next attempt, in 1840, was successful in making variolation a felony, and in throwing on the rates the cost of vaccinating the infants of the poorer classes. The danger of contagion from inoculated smallpox in 1840 was no greater than it had ever been, and it had never been appreciable among the things favouring an epidemic. The common-law maxim, “sic utere tuo ut alienum non laedas,” which gained statutory force as against inoculation by the Act of 1840, was farther extended and specifically applied in the Act of 1853, which enforced the inoculation of cowpox upon all infants before they were three months old. Legislation, as we know, broadens down from precedent to precedent. Parliament in 1853 did not debate the preamble of the Bill, but accepted the principle established by the Act of 1840,--in the constructive sense that to leave infants without the inoculation of cowpox was, in effect, “to expose them so as to be infectious,” because they were sure to take smallpox, and so to become nuisances to others “unprotected” as well as (less obviously) to their cowpoxed neighbours. Other effects of the epidemic of 1837-40 on medical opinion. A second inoculation, except as a mere test of the first and within a few weeks thereof, was no part of the original 18th century teaching and practice. The theory of inoculation being based upon the familiar experience that we seldom have the same infectious disease twice in a lifetime, it was held that inoculation, if it were effective, was the giving of smallpox once for all, and that it could not really be given a second time unless the first inoculation had been ineffective. As soon as cowpox was recommended, it was remarked as a strange thing that this disease, according to current accounts of it, was actually acquired by milkers time after time. That fact in its natural history, said the _Medical and Physical Journal_ of January, 1799, was “received with general scepticism merely on account of its improbability.” Dr Pearson was so troubled by the apparent inconsistency that he wrote to Dr Jenner in 1798 to ask whether it were really so; and although the latter confirmed the matter of fact, Pearson went on denying it, and did actually deny it as late as the Report of the Vaccine Pock Institution for 1803. Again, the report of the Whitehaven Dispensary for 1801, while it admitted the matter of fact, adverted to the anomaly in these words: “As we know from experience that the cowpock can be repeatedly introduced by inoculation, it appears remarkable that it can act as a preventive of a similar equally specific but more malignant disease.” Those were theoretical difficulties, which the practical minds of the profession did not stand upon. When we next hear of the possibility of having cowpox more than once, it is no longer an intellectual stumbling-block but is turned to account in the way of re-vaccination. _Lapidem quem reprobaverunt aedificantes, hic factus est in caput anguli._ The practice of re-vaccination was usual on the Continent long before the English took to it. The reason of this was that a second inoculation of cowpox was not resorted to for the greater security of infants and young children, who were then the principal victims of smallpox in this country, but for the protection of adults, who made a great part of the subjects of the epidemics in other countries. There were so many adult deaths in the great Paris epidemic of 1825 that the news of it reads like the English references to smallpox in the time of the Stuarts. We obtain exact statistics of the ages in the 3323 fatal cases of smallpox in Paris from 1842 to 1851. Reduced to percentages they were as follows: All ages 0-5 5-10 10-20 20-30 30-40 Over 40 100 33·8 5·9 13·25 32·95 10·95 3·15 Two-thirds of the deaths were above the age of five years, an age-incidence that was not reached in London until a whole generation after. The contrast with British experience comes out in concrete form in the following table of the age-incidence of 342 fatal attacks of smallpox in 1850 and 364 in 1851, in Paris (pop. 1,000,000), and of 584 fatal attacks in Glasgow in the single year 1852 (pop. 370,000)[1170]: _Age-incidence of fatal Smallpox in Paris and in Glasgow._ Paris, 1850-51 Glasgow, 1852 (706 deaths) (584 deaths) Under one year 126 188 One to two 32 150 Two to five 94 189 Five to ten 31 20 Ten to fifteen 20 4 Fifteen to twenty 51 2 Twenty to twenty-five 109 19 Twenty-five to thirty 89 2 Thirty to forty 128 8 Forty to fifty 22 1 Over fifty 4 1 In other parts of the Continent of Europe the frequency of smallpox in adults was not less remarked than in France in the second quarter of the 19th century. English writers had been able at one time to point to foreign countries for the success of infantile vaccination. Sweden and Denmark were for a long time classical illustrations; then it was Germany’s turn. “In Berlin during 1821 and 1822,” said Roberton, “only one died of smallpox in each year. In the German States, vaccination has become universal, and in them as well as in various other countries the smallpox is almost unknown.” When we next find German experience appealed to, it is to enforce the need of re-vaccination: “In 1829,” said Gregory, “the principal Governments of Germany took alarm at the rapid increase of smallpox, and resorted to re-vaccination as a means of checking it. In Prussia, 300,000 had been re-vaccinated, and the same number in Würtemberg. In Berlin nearly all the inhabitants had undergone re-vaccination[1171].” It was about the same time that a second vaccination became obligatory in the armies of Prussia, Würtemberg, Baden and other German States, and among the pupils of schools when they reached the age of twelve years. Dr Gregory, in his speech at the Medical and Chirurgical Society of London in December, 1838, urged the need of re-vaccination not only by the example of Germany, but also by the experience of Copenhagen, where a thousand cases of smallpox had been received into the hospital (it was nearly always adults that were taken to the general hospitals) in twenty-one months of 1833-34, nine hundred of them being of vaccinated persons[1172]. Gregory was in advance of his age in advocating re-vaccination for England. His own cases at the Smallpox Hospital of London were, it is true, nearly all adults, according to the rules of the charity. But they were not representative even of the smallpox of the capital; and in England at large smallpox in 1839 was still distinctively a malady of the first years of life. It was not until youths and adults began to have smallpox in large numbers in the epidemic of 1871-72 that the doctrine of re-vaccination was generally apprehended in England. Medical truth, like every other kind of truth except that of geometry, is conditioned by time and place. What was a truth to the Germans in 1829 was not a truth to us until some forty years after. Dr Gregory, Sir Henry Holland and others advised re-vaccination after the epidemic of 1837-40; but as late as 1851 the National Vaccine Establishment denounced it as incorrect in theory and uncalled-for in practice. * * * * * After the great epidemic of 1837-40, there was an interval of a whole generation until smallpox broke out again on anything like the same scale, in 1871 and 1872. But it had risen to a considerable height at shorter intervals--in 1844-45, which were the years when vast numbers of navvies were employed making railroads all over England, in 1847 and successive years to 1852, which was the period of the great Irish migration after the potato-famine, in 1858, for which I find no explanation, and in the period from 1863 to 1865, which was again a time of somewhat high typhus mortality, not only in the Lancashire cotton-districts but also in London. The great epidemic of 1871 and 1872 finds no better explanation than our neighbourhood to Germany and Belgium, where the mortality from smallpox was far greater than in Britain, and was doubtless favoured by the state of war in 1870-71. The following tables for London, and for England and Wales in comparison with measles, scarlatina and diphtheria, show the progress of smallpox from the epidemic of 1837-40 to the present time: _Smallpox Deaths in London from the beginning of Registration._ Year Deaths 1837 (6 mo.) 763 1838 3817 1839 634 1840 1235 1841 1053 1842 360 1843 438 1844 1804 1845 909 1846 257 1847 255 1848 1620 1849 521 1850 499 1851 1062 1852 1150 1853 211 1854 694 1855 1039 1856 531 1857 156 1858 242 1859 1158 1860 898 1861 217 1862 366 1863 1996 1864 547 1865 640 1866 1391 1867 1345 1868 597 1869 275 1870 973 1871 7912 1872 1786 1873 113 1874 57 1875 46 1876 736 1877 2551 1878 1417 1879 450 1880 471 1882 430 1883 146 1884 898 1885 914 1886 5 1887 7 1888 5 1889 0 1890 3 1891 1 1892 11 1893 206 _England and Wales: Deaths by Smallpox, Measles, Scarlatina and Diphtheria from the beginning of Registration._ Smallpox Measles Scarlet Fever Diphtheria 1837 (½) 5811 4732 2550 -- 1838 16268 6514 5862 -- 1839 9131 10937 10325 -- 1840 10434 9326 19816 -- 1841 6368 6894 14161 -- 1842 2715 8742 12807 -- 1847 4227 8690 14697 -- 1848 6903 6867 20501 -- 1849 4644 5458 13123 -- 1850 4665 7082 13371 -- 1851 6997 9370 13634 -- 1852 7320 5846 18887 -- 1853 3151 4895 15699 -- 1854 2868 9277 18528 -- 1855 2523 7354 16929 385 1856 2277 7124 13557 603 1857 3236 5969 12646 1583 1858 6460 9271 23711 6606 1859 3848 9548 19310 10184 1860 2749 9557 9681 5212 1861 1320 9055 9077 4517 1862 1638 9860 14834 4903 1863 5964 11340 30473 6507 1864 7684 8322 29700 5464 1865 6411 8562 7700 4145 1866 3029 10940 11683 3000 1867 2513 6588 12380 2600 1868 2052 11630 21912 3013 1869 1565 10309 27641 2606 1870 2620 7543 32543 2699 1871 23062 9293 18567 2525 1872 19022 8530 11922 2152 1873 2308 7403 13144 2531 1874 2084 12235 24922 3560 1875 849 6173 20469 3415 1876 2468 9971 16893 3151 1877 4278 9045 14456 2731 1878 1856 9765 18842 3498 1879 536 9185 17613 3053 1880 648 12328 17404 2810 1881 3698 7300 14275 3153 1882 1317 12711 13732 3992 1883 957 9329 12645 4218 1884 2216 11324 11143 5020 1885 2827 14495 6355 4471 1886 275 12013 5986 4098 1887 506 16765 7859 4443 1888 1026[1173] 9784 6378 4815 1889 23 14732 6698 5368 1890 16 12614 6974 5150 1891 49 12673 4959 5036 1892 431 13553 5618 6552 1893 1455 10764 6869 8918 The great epidemic of 1837-40 was the last in England which showed smallpox in its old colours. The disease returned once more as a great epidemic in 1871-72, after an interval of a whole generation (in which there had been, of course, a good deal of smallpox); but the epidemic of 1871-72 was different in several important respects from that of 1837-40. It was a more sudden explosion, destroying about the same number in two years (in a population increased between a third and a half) that the epidemic a generation earlier did in four years. It was an epidemic of the towns and the industrial counties, more than of the villages and the agricultural counties; it was an epidemic of London more than of the provinces; and it was an epidemic of young persons and adults more than of infants and children. The great epidemic of 1871-72 brought out clearly for the first time all those changes in the incidence of smallpox; but things had been moving slowly that way in the whole generation between 1840 and 1871. Experience subsequent to 1871-72 has shown the same tendency at work. To begin with the changed incidence upon rural and urban populations, a glance down the following Table, will show that the counties marked *, with a smaller share in 1871-72, in a total of deaths in all England and Wales which was nearly the same as in the great epidemic a generation before, are nearly all those with a population more purely rural[1174]: _Incidence of the Smallpox Epidemics of 1837-40 (four years) and 1871-72 (two years) respectively upon the Counties of England and Wales._ 1837-40 1871-72 England and Wales 41,253 42,084 Metropolis 6421 9698 *Surrey (extra-metr.) 383 231 *Kent (extra-metr.) 817 537 *Sussex 161 126 Hampshire 348 1103 *Berkshire 450 46 *Middlesex (extra-metr.) 418 306 *Hertfordshire 260 157 *Buckinghamshire 268 53 *Oxfordshire 199 109 Northamptonshire 399 563 *Huntingdonshire 65 14 Bedfordshire 125 128 *Cambridgeshire 400 175 *Essex 773 583 *Suffolk 506 348 *Norfolk 1038 895 *Wiltshire 548 85 *Dorsetshire 329 163 *Devonshire 1097 838 *Cornwall 767 531 *Somersetshire 1466 412 *Gloucestershire 1072 323 *Herefordshire 191 34 *Shropshire 345 161 *Worcestershire 1002 529 Staffordshire 1328 3050 *Warwickshire 957 785 Leicestershire 528 622 Rutlandshire 8 7 Lincolnshire 482 498 Nottinghamshire 562 983 *Derbyshire 329 297 *Cheshire 1141 310 †Lancashire 7105 4151 †Yorkshire W. Riding 2858 2609 " E. Riding 480 452 " N. Riding 236 405 Durham 798 4767 Northumberland 569 1512 *Cumberland 549 366 *Westmoreland 98 41 Monmouthshire 672 904 *Wales 2699 2314 The counties which were most lightly visited in 1871-72, as compared with 1837-40, were the agricultural and pastoral. In the outbreaks subsequent to 1871-72, smallpox has almost ceased to be a rural infection in Scotland and Ireland as well as in England. The great change that has come over it in that respect is shown in the following table, in which the annual death-rates from smallpox per 100,000 living are contrasted, for children under five, in each of several agricultural counties, with the mean of all England and of London, 1871-80, and with the corresponding scarlatinal death-rates in the right-hand column: _Annual Death-rates of Children under five, per 100,000 living, 1871-80._ Smallpox Scarlatina All England 53 349 London 113 307 ------------------------------------------- Sussex 9 100 Berkshire 4 141 Bucks 4 160 Oxfordshire 9 167 Huntingdonshire 3 205 Bedfordshire 11 242 Cambridgeshire 18 112 Suffolk 12 136 Wiltshire 5 210 Dorsetshire 15 152 Herefordshire 5 166 Shropshire 12 247 But the history of smallpox since the great epidemic of 1871-72 has brought out still another tendency in the same direction, namely, the increasing share of London in the whole smallpox of England. In the epidemic of 1837-40, which reached to almost every parish of England and Wales, London had 6449 deaths in a total of 41,644, or between a sixth and a seventh part, having rather less than an eighth part of the population. In the epidemic of 1871-72, London had between a fourth and a fifth part of the deaths (9698 in a total of 42,084), having then about a seventh part of the population. In 1877, more than half of all the smallpox deaths were in London, and in the year after as many as 1417 in a total of 1856. In 1881, London had about two-thirds of the deaths from smallpox in all England and Wales; but in the epidemic of 1884-85, it had only over a third part (1812 in a total of 5043). This excess of London’s share over that of the provinces is expressed in the following table, showing the respective rates of smallpox mortality per million of the population: _Smallpox Deaths in London and the Provinces, per million of population._ 1847-9 1850-4 1855-9 1860-4 1865-9 1870-4 1875-9 1880-4 London 460 300 237 281 276 654 292 244 Provinces 274 271 192 175 172 339 48 34 If the table were continued to the very latest date, it would show the provinces recovering their share, but upon a slight prevalence of the epidemic as a whole, the deaths in London having been mere units from 1886 to 1892, while in 1888 there was a severe epidemic in Sheffield and in 1892-93 a good deal of the disease in a few manufacturing towns of the North-western and Midland divisions. It would be a not incorrect summary of the incidence of smallpox in Britain to say, that it first left the richer classes, then it left the villages, then it left the provincial towns to centre itself in the capital; at the same time it was leaving the age of infancy and childhood. Of course it did none of these things absolutely; but the movement in any one of those directions has been as obvious as in any other. Measles and scarlatina have not shown the same tendency to change or limit their incidence. Smallpox may have surprises in store for us; but, as it is an exotic infection, its peculiar behaviour may not unreasonably be taken to mean that it is dying out,--dying, as in the death of some individuals, gradually from the extremities to the heart. With all those changes, the fatality of smallpox, or the proportion of deaths to attacks, came out in the great epidemic of 1871-72 curiously near that of the 18th century epidemics, namely, one death in about six cases. This rate comes from the hospitals of the Metropolitan Asylums Board according to the following table: _Admissions for Smallpox, with the Deaths, at the hospitals of the Metropolitan Asylums Board, from the opening of the several hospitals to 30 April, 1872._ Males Females Both Sexes Age-periods Percentage Percentage Percentage of of of Adm. Died deaths Adm. Died deaths Adm. Died deaths Under 5 434 235 54·15 | 469 236 50·32 | 903 471 52·15 5-10 851 236 27·73 | 821 196 23·87 | 1672 432 25·83 10-20 2827 265 9·37 | 2513 237 9·43 | 5340 502 9·40 20-30 2561 465 18·15 | 1922 285 14·82 | 4483 750 16·72 30-40 939 244 26·00 | 665 136 20·45 | 1604 380 23·69 40-50 316 100 31·64 | 242 64 26·45 | 558 164 29·39 50-60 85 18 21·17 | 88 31 35·22 | 173 49 28·32 Above 60 40 8 20·00 | 35 7 20·00 | 75 15 20·00 --- --- | --- --- | --- --- 8053 1571 19·49 | 6755 1192 17·64 |14,803 2763 18·65 These admissions to hospitals included attacks of every degree of severity, the intention of the hospitals being to isolate all cases, mild and severe alike; so that, although these are technically hospital cases, they are not comparable to the select class admitted to the old Smallpox Hospital of London, but to the cases of smallpox in former times in the community at large. Although the general average of deaths in 14,808 cases, namely, 18·65 per cent., is nearly the same as (being slightly higher than) that of the equally comprehensive totals of 18th century cases given at p. 518, yet the average is made up in a different way. In some of the 18th century epidemics, such as that of Chester in 1774, all the deaths were under ten years of age, and yet the average rate of fatality was only 14 or 15 per cent. The much higher rate of fatality from birth to five years and from five years to ten in the London epidemic of 1871-72 (which is confirmed in part by the Berlin statistics of the same years), must have had some special reasons. One reason, doubtless, was that the attack of smallpox in recent times has fallen upon comparatively few children, whereas in former times it fell upon nearly the whole; and it may be inferred that the infants who have been in recent times subject to the attack of smallpox have also been of the class that are most likely to die of it. The high rates of fatality at the ages above thirty in the table agree with the experience of all times. The percentages of fatalities from smallpox in the hospitals of the Metropolitan Asylums Board have varied as follows from their opening to the present time: Percentage Cases of deaths 1 Dec. 1870-3 Feb. 1871 582 20·81 4 Feb. 1871-31 Jan. 1872 13,145 18·95 1872-3 2362 17·84 1873-4 191} 1874 (11 mo.) 120} 17·02 1875 111} 1876 2150 21·64 1877 6620 17·92 1878 4654 17·99 1879 1688 15·69 1880 2032 15·95 1881 8671 16·61 1882 1854 12·96 1883 626 16·06 1884 6567 15·98 1885 6344 15·8 1886 132} 1887 59} 1888 67} 14·28 1889 5} 1890 27} 1891 64} 1892 348 11·29 1893 2376 7·75 The decline in average fatality in the last two years is remarkable, and is to be explained chiefly by the mild type of smallpox which has been prevalent; a very small fraction of the patients attacked between the ages of ten and twenty-five have died; and these are some two-fifths of the whole. This is shown in the following age-table of 2374 cases admitted to the Metropolitan Board Hospitals in 1893: _Smallpox in London, 1893._ Age-period Cases Deaths % 0-5 168 53 31·5 5-10 191 16 8·3 10-15 230 7 3·0 15-20 340 7 2·0 20-25 393 13 3·3 25-30 298 23 7·7 30-35 250 14 5·6 35-40 182 13 7·1 40-50 199 18 9·0 50-60 79 9 11·4 60-70 35 6 17·1 70-80 9 1 11·1 The low rate of fatality during the slight epidemic revival of smallpox in 1892-93 has been found to obtain wherever the disease has occurred: _Smallpox in the Provinces, 1892-93._ Fatalities Cases Deaths per cent. Birmingham 1203 96 8 Warrington 598 60 10 Halifax 513 44 8·5 Manchester 406 27 6·7 Glasgow 279 23 8·2 Liverpool 194 15 7·7 Brighouse 134 15 11·2 Aston Manor 113 6 5·3 Leicester 362 21 5·8 St Albans 58 6 10·4 ---- --- ---- 3860 313 8·10 The ages under ten years had only 290 in 3644 of these cases; but those 290 cases had 70 in 302 of the deaths. In the comparative table for Ireland, of deaths by smallpox, measles, scarlatina and diphtheria, measles in a decreasing population has changed little, while scarlatina has declined greatly, and smallpox has fallen during the last ten years almost to extinction. _Ireland: Deaths by Smallpox, Measles, Scarlatina and Diphtheria from the beginning of Registration._ Smallpox Measles Scarlatina Diphtheria 1864 854 630 2605 661 1865 461 1036 3683 480 1866 194 851 3501 317 1867 21 1292 2145 189 1868 23 1251 2696 202 1869 20 948 2670 243 1870 32 954 2978 188 1871 665 547 2707 226 1872 3248 1380 2459 257 1873 504 1303 2092 326 1874 569 667 4034 565 1875 535 898 3845 443 1876 24 664 2112 368 1877 71 1562 1117 288 1878 873 2212 1079 296 1879 672 860 1688 320 1880 389 1025 1344 314 1881 72 402 1230 323 1882 129 1518 2443 385 1883 16 801 1765 239 1884 1 559 1377 354 1885 4 1323 1147 296 1886 2 284 850 336 1887 14 1307 973 381 1888 3 1935 849 447 1889 0 574 457 358 1890 0 726 319 346 1891 7 240 308 281 1892 0 1183 419 286 In the great Irish famine of 1846-49, comparatively little is heard of smallpox. It would appear to have been less diffused through the country than in former famines, such as that of 1817-18, or those of the first part of the 18th century, just in proportion as the vagrancy of famine-times was checked by the establishment of workhouses. In the workhouses and auxiliary workhouses during the ten years 1841-51, smallpox is credited with 5016 deaths, while measles has 8943, fever 34,644, dysentery 50,019, diarrhoea 20,507, and Asiatic cholera 6716. Registration began in Ireland in 1864, and showed little smallpox for the first few years. The next great epidemic, of 1871-72, showed the incidence upon the large towns, and the comparative immunity of the country population, even more strikingly than in England. In a total mortality of 3913 during the two years of 1871 and 1872, the three counties of Dublin, Cork and Antrim had the following enormous share, which fell mostly to the three cities of Dublin, Cork and Belfast: Dublin Co. 1825 Cork Co. 1070 Antrim 510 ----- 3405 deaths in 3913 for all Ireland. In that epidemic the whole province of Connaught had only 25 deaths from smallpox; but a subsequent visitation, a few years after, fell mainly upon Connaught. The epidemic which began in Scotland in 1871 was distributed over a somewhat longer period than the corresponding outbreak in England; but the bulk of it fell in the two years 1871 and 1872. The total of 3890 deaths in those two years was distributed as follows: Eight largest towns 2441 Next largest towns 259 Small town districts 574 Mainland rural districts 586 Insular rural districts 30 ---- 3890 Glasgow had a considerably smaller relative share than Edinburgh, and altogether a much lighter incidence of the disease than in the years 1835-52, for which the figures have been given above (pp. 600-1). In the following table of the annual deaths in Scotland from the beginning of registration, the four other infective diseases of childhood included along with smallpox show by comparison the remarkable decline of smallpox since 1874, scarlatina being the only other infection of childhood which has become greatly less common or less fatal. _Scotland. Deaths by Smallpox, Measles, Scarlatina, Diphtheria and Whooping-Cough, from the beginning of Registration._ Smallpox Measles Scarlatina Diphtheria Whooping-Cough 1855 1209 1180 2138 -- 1903 1856 1306 1033 3011 -- 2331 1857 845 1028 2235 76 1539 1858 332 1538 2671 294 1963 1859 682 975 3614 415 2660 1860 1495 1587 2927 480 1812 1861 766 971 1764 681 2204 1862 426 1404 1281 997 2799 1863 1646 2212 3413 1745 1649 1864 1741 1102 3411 1740 1993 1865 383 1195 2244 995 2318 1866 200 1038 2706 685 1860 1867 100 1341 2253 610 1728 1868 15 1149 3141 749 2490 1869 64 1670 4680 663 2461 1870 114 834 4356 630 1783 1871 1442 2057 2586 880 1504 1872 2448 925 2101 1045 2850 1873 1126 1450 2227 1203 1598 1874 1246 1103 6321 1163 1690 1875 76 1022 4720 867 2431 1876 39 1241 2364 861 2250 1877 38 1019 1374 956 1571 1878 4 1372 1870 1033 2788 1879 8 769 1592 862 2483 1880 10 1427 2165 838 2641 1881 19 1012 1573 816 1620 1882 3 1289 1583 961 2108 1883 11 1629 1336 747 2968 1884 14 1440 1266 830 2511 1885 39 1426 944 688 2157 1886 24 681 1058 583 1882 1887 17 1598 1179 805 3212 1888 3 1406 732 872 1722 1889 8 1948 701 968 2268 1890 0 2509 739 1018 3039 1891 0 1775 736 830 2437 The age-incidence of Smallpox in various periods of history. Among the various changes of incidence that have attended the recent decline of smallpox in England, Ireland and Scotland, there is one that calls for more extended notice, namely, the fact that the malady has in great part ceased to be an infection of infancy and childhood and has become more distinctively an infection of adolescence and mature age. In no period of its history has smallpox been so purely an infantile complaint as measles[1175], nor so purely a malady of childhood and early youth as scarlatina or diphtheria[1176]. When it first rose to prominence in England, from the reign of James I. onwards, it attacked adults in a large proportion; of which fact the evidence, although not statistical, is sufficient. But, as the disease became nearly universal and ubiquitous, it was so commonly passed in infancy or childhood, that few grew to maturity without having had it. The number of adult cases diminished in proportion as the disease became more nearly universal. In the great period of smallpox in the 18th century, about nine-tenths of the deaths occurred under the age of five, and nearly all the remaining fraction between five and ten years, at Manchester, Chester, Warrington, Carlisle and Kilmarnock. But in London there were always a good many adult deaths, the reason commonly given being that there was a steady influx to the capital of domestic servants and others from country parishes where the epidemics came at sufficiently long intervals to let many children grow up without incurring the risk of it. Also at Geneva and the Hague, in the 18th century, there were many more deaths above the age of five than in the English provincial towns at the same time. _Ages at Death from Smallpox at Geneva (including Measles) and at the Hague (Duvillard)._ All 0-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -15 -20 ages Geneva (1700-83)} 3328 555 608 588 426 346 232 185 99 67 44 84 36 The Hague} (15 years} of } 1455 172 170 179 224 160 148 114 78 58 23 47 17 18th } cent.) } -25 -30 -35 -40 -45 Geneva (1700-83)} 26 21 0 0 0 The Hague} (15 years} of } 24 14 10 8 3 18th } cent.) } Twenty-four per cent. of the smallpox deaths in the 18th century at Geneva were above the age of five years, and at the Hague thirty-seven per cent., while in the former the ratio would probably have been higher but for the inclusion of measles. But, with this comparatively high ratio of deaths above the age of five, smallpox was a much less important cause of mortality at Geneva and the Hague than at Manchester, Glasgow, Chester, and most other provincial cities of this country, making about a fifteenth part of the deaths from all causes in the former, and as high as a sixth part in the latter. The infantile character of smallpox was as marked as ever in the epidemic of 1817-19; of which the Norwich statistics are sufficient proof. As late as the epidemic of 1837-40, smallpox was still distinctively a malady of infants and young children in Britain, although that was by no means the case on the continent of Europe at the same time. The following was the age-incidence of fatal smallpox at Liverpool and Bath in the last six months of 1837. At all Under Above ages 1 1-2 2-3 3-4 4-5 5-6 6-10 10 Liverpool Deaths 495 143 127 77 64 24 19 20 25 +------+ +------+ Ratios 100 28·65 25·45 15·43 17·63 7·81 5·01 per cent. Bath Deaths 151 33 31 33 17 17 6 6 10 +------+ +-----+ Ratios 100 21·56 20·26 21·56 22·2 7·84 6·53 per cent. In the third year of the epidemic, 1839, the ratio of deaths above the age of five was still less at Manchester, Liverpool and Birmingham, being only four and a half per cent. (26 in a total of 522). At Glasgow, from 1835 to 1839, twelve per cent. of the smallpox deaths were above the age of five (see p. 600). These are the rates of provincial cities; but in a total of 8714 deaths in the year 1839, added together from London and the provinces, about twenty-five per cent. were over five, and of these a moiety were over ten years: All ages Under five Five to ten Above ten 8714 6453 1122 1139 A good deal of that mortality above the age of five must have come from London, according to the probability of the following table, which is of six years’ later date, but the nearest that can be got for London alone: _London, 1845. Ages at Death from Smallpox, Measles and Scarlatina._ Smallpox Measles Scarlatina Total at all ages 909 2318 1085 ----------------------------------------------------- Under One year 209 353 88 One to Two 133 832 167 Two to Three 91 511 181 Three to Four 81 272 183 Four to Five 63 153 115 Five to Ten 136 168 254 Ten to Fifteen 33 18 46 Fifteen to Twenty 34 3 14 Twenty to Twenty-five 54 1 8 Twenty-five to Thirty 38 2 6 Above Thirty 37 5 23 The ratio of smallpox deaths above five was 37·5 per cent., of measles deaths 8·4 per cent., and of scarlatina deaths 32·3 per cent. Measles and scarlatina have kept these ratios somewhat uniformly to the present time, but the ratio of smallpox deaths above the age of five has increased according to the following table for England and Wales from 1851 to 1890: Percentage of Percentage of Percentage of smallpox deaths measles deaths scarlatina deaths Period above five years above five years above five years 1851-60 38 10 36 1861-70 46 8 36 1871-80 70 8 34 1881-90 77 8 36 The progressive raising of the age of fatal smallpox is shown in another way by taking the ratio of the deaths per million living at all ages and at each of eleven age-periods[1177]: _Smallpox Deaths per million living at each age-period._ Period All 75 and ages 0- 5- 10- 15- 20- 25- -35 -45 -55 -65 over 1851-60 221 1034 257 73 93 130 92 53 38 24 18 14 1861-70 163 654 145 56 86 136 102 73 49 36 26 22 1871-80 236 527 284 137 197 300 239 168 111 71 46 35 It was the great epidemic of 1871-72 that brought out the change of age-incidence most concretely, just as it brought out, in contrast to the last great epidemic in 1837-40, the decline in the rural and the increase in the industrial centres. In the three years before the outburst of 1871 the deaths under five and over five were approaching an equality; in the epidemic itself the old ratios were suddenly reversed: Smallpox deaths Smallpox deaths Year under five over five 1868 1234 818 1869 892 673 1870 1245 1375 1871 7770 15356 1872 5758 13336 In the whole generation between 1840 and 1871, in which there was no great and general epidemic of smallpox, many had passed from childhood to adolescence and maturity without encountering the risk of it. When the epidemic of 1871 began, it found many in youth or mature years who had not been through the smallpox, and it attacked a certain proportion of them accordingly. The proportion above the age of five so attacked in 1871-72 was greater than it had been in this country since the beginning of the 18th century; indeed, as the information is not in statistical form for the earlier period, it may be asserted, and it may happen to be true, that it was greater than it had ever been in this country at any time. The reason for the large proportion of adult cases was the same in the rise of smallpox as in its decline, namely, that in the respective circumstances an epidemic found many who had not been through the disease in infancy or childhood. The same happened in those parts of the world where the epidemics of smallpox came at long intervals, during which many had passed from childhood to youth or mature age without once encountering the risk of smallpox. Such were the epidemics at Boston, New England, and Charleston, South Carolina, in the 18th century. Not only do the accounts of them speak of the disease as if it were mainly one of the higher ages, but it follows from the ratio of attacks to population, known in the case of Boston, that adolescence and adult age must have had a full share, considering that these age-periods included all who were protected by a previous attack. The years of epidemic smallpox at Boston were 1702, 1721, 1730 and 1752: of these four the two worst were 1721 and 1752, the one epidemic following a clear interval of nineteen years, the other a more or less clear interval of twenty-two years: _Smallpox in Boston, Massachusetts_[1178]. Population, Attacked Died Had Moved whites by of smallpox out and blacks smallpox smallpox before of town 1721 10,565 5989 844 All the -- rest less 750 1752 15,684 5545 569 5598 1843 These enormous mortalities in Boston were comparable to those of the old plague itself in European cities, not only in falling upon all ages but also in doubling or trebling for a single year at long intervals the annual average of deaths: Deaths of Deaths of whites blacks Total 1701 146 -- 146 *1702 441 -- 441 1720 261 68 329 *1721 968 134 1102 1722 240 33 273 *1730 740 160 909 1731 318 90 408 *1752 893 116 1009 * Smallpox years. Just as smallpox in its first great outbursts in the London of the Stuarts, or in its rare outbreaks in the American colonies in the 18th century, fell impartially upon children and adults, so in its last outbursts in the London of Victoria it fell upon persons at all ages. The notable thing is, not that smallpox should have of late been attacking adults, for that it has ever done except in times and places in which there were few or no adults who had not been through the disease in childhood; but that it should have ceased to so large an extent to attack infants and children. It has ceased to attack infants and children because other infective and non-infective diseases more appropriate to the modern conditions of the population are attacking them instead. These are measles and whooping-cough, scarlatina and diphtheria, infantile diarrhoea, and the more chronic after-effects of these. The annual death-rate from all diseases under the age of five has fluctuated somewhat per million living from 1837 to the present time, but it can hardly be said that it has fallen much or steadily[1179]. Keeping still to the epidemic of 1871-72, let us consider whether there was any natural or epidemiological reason for its cutting off a smaller ratio of infants and children in its whole mortality than that of 1837-40 did. There had been a most disastrous epidemic of scarlatina for three years just before, which had caused 21,912 deaths in 1868, 27,641 in 1869, and 32,543 in 1870, a total of 82,096 in three years, about two-thirds of which were under the age of five, or at the age-period which smallpox used to be fatal to almost exclusively and to be the greatest single epidemic scourge of. Even in the two smallpox years themselves the scarlatinal deaths were 18,567 and 11,922, of which the share that fell to children under five was one and a half times the deaths in that age-period from the co-existing smallpox. The three years of excessive scarlatina, before the epidemic of smallpox began, had removed large numbers of the class of infants and children who succumb to any infectious disease; if we cannot give the whole _rationale_ of one infection dispossessing or anticipating another, we can at least understand that the earlier and more dominant infection takes off the likely subjects. What scarlatina did egregiously during the three years just before the great explosion of smallpox, it had been doing steadily (along with measles, &c.) throughout a whole generation since the last great sacrifice of infants and children by smallpox in 1837-40. But the fact that scarlatina had in great part dispossessed smallpox among the factors of mortality under the age of five, did not prevent the latter infection from attacking those of the higher ages who were susceptible of it and were at the same time unvexed by any other great epidemic malady proper to their time of life. If the epidemic of smallpox in 1871-72 had cut off as large a ratio under the age of five years as its immediate predecessor in 1837-40 did, its whole mortality would have been about 70,000 more than it actually was. But in no state of the population or of the public health can we suppose that three years of excessive mortality of children by one kind of contagion would be followed immediately by two years of equally special mortality at the same ages by contagion of another kind. It is not only epidemiological science that tells us this, but also common sense--_est modus in rebus_. The saving of life by checking the prevalence of smallpox was a favourite rhetorical topic in the 18th century. Voltaire, La Condamine, Bernoulli, Watson, Haygarth and others, were fond of estimating how many thousands of lives might be saved in a year if inoculation were thoroughly carried out. Dr Lettsom, Sir Thomas Bernard and Mr James Neild, who were interested in prison reforms and in whatever else would reduce the prevalence of typhus, reckoned the possible saving of life under that head as almost equal to the possible saving from smallpox[1180]. For typhus there was no artificial means of restraint; it had to decline before natural causes, if it declined at all,--which, indeed, it has done. But no one at that time thought of keeping down smallpox except by the inoculation of itself or of cowpox. The economists and statisticians treated each of these artifices in its turn as a factor having a certain absolute value, which they might use like the _a_ and _b_ of a problem in algebra. This they did, of course, in deference to medical authority. What Bernoulli had worked out for the old inoculation, Duvillard did for the new, in his “Tables showing the Influence of Smallpox on the Mortality of each period of Life, and the Influence that such a preservative as Vaccine may have on the Population and on Longevity[1181].” Malthus fell into the conventional way of thinking when he assumed that smallpox alone among the epidemic checks of population was to be controlled artificially; but he introduced an important new consideration. “For my own part,” he wrote in 1803, “I feel not the slightest doubt, that if the introduction of the cowpox should extirpate the smallpox, and yet the number of marriages continue the same, we shall find a very perceptible difference in the increased mortality of some other diseases[1182].” Five years after this was written, there came, in 1808, the disastrous epidemic of measles, which in Glasgow killed more infants in a few months than smallpox had ever done at its worst in the same city. In the winter of 1811-12 there was another severe epidemic of measles in Glasgow; and in 1813, Dr Watt, a leading physician of the place, and a man now famous in all countries for his vast labours as a bibliographer, gave to the world his statistical proof, from the Glasgow burial registers, of that law of substitution which Malthus had found necessary in his deduced principles. “The first thing,” said Watt, “that strikes the mind in surveying the preceding Table (1783-1812), is the vast diminution in the proportion of deaths by the smallpox, a reduction from 19·55 to 3·90. But the increase in the subsequent column [measles] is still more remarkable, an increase from 0·95 to 10·76. In the smallpox we have the deaths reduced to nearly a fifth of what they were twenty-five years ago [in ratio of the deaths from all causes]; in the same period the deaths by measles have increased more than eleven times. This is a fact so striking that I am astonished it has not attracted the notice of older practitioners, who have had it in their power to compare the mortality by measles in former periods with what all of them must have experienced during the last five years[1183].” The high ratio of measles and the low ratio of smallpox did not remain as Watt’s researches left them. When Cowan resumed the tabulation of figures from 1835 to 1839 he found the ratios of those two infantile infections almost equal, and the two together contributing to the whole mortality of Glasgow only a little more than half their joint share in the end of the 18th century. The substitution which Watt saw during a few years was only the most dramatic part of a general movement forwards of measles among the causes of infantile mortality. He supposed, as everyone did at that time, that smallpox was forcibly repressed, and that another infectious disease had seized the opportunity to become exuberant. The most relevant thing in the whole situation was urged by those who thought, with Jenner, that the doctrine of substitution had an “evil tendency” as detracting from the absolute value of the inoculation principle. In order to discredit Dr Watt altogether, they pointed out that his ratios of smallpox and measles took no account of the diminished death-rate of Glasgow by all diseases in the earlier years of the 19th century. Great changes were proceeding in the old city, the Glasgow of ‘Rob Roy.’ The population which was reckoned at 45,889 in the year 1785, had increased to 66,578 in the year 1791, and thereafter, at a slower rate, to 83,769 in 1801 and to 100,749 in 1811. The first great increase after the American War meant overcrowding; but in a short time new suburbs spread over such an extent that, in the year 1798, more than half the burials were in the graveyards attached to chapels-of-ease and meeting-houses outside the original parishes. The modern expansion of Glasgow, like that of London and of all other large cities, has been an increase of area still more than an increase of numbers. The public health improved steadily, at all events until 1817, the improvement being shown first in the increasing number of infants that survived their second year. That rise in the probability of life corresponded to the substitution of measles for smallpox, and in part depended upon the ascendancy of the milder infection. Still more remarkable was the rise of scarlatina, which Dr Watt did not live to see; so little was made of it at the date of his writing that he found “scarlatina, typhus, &c., all comprehended under the same head.” The seeds of measles and scarlatina had long existed beside the seeds of smallpox, but the ascendancy of each of the two former had to wait events. Said Banquo to the witches who hailed Macbeth as king and himself as the sire of later kings: “If you can look into the seeds of time, And say which grain will grow, and which will not--” The succession of reigning infections is the same problem. All we can say is that each new predominant type is somehow suited to the changed conditions. In the long period covered by this history we have seen much coming and going among the epidemic infections, in some cases a dramatic and abrupt entrance or exit, in other cases a gradual and unperceived substitution. Some of the greatest of those changes have fallen within the two hundred years since Sydenham kept notes of the prevalent epidemics of London. We are that posterity, or a generation of it, which he expected would have its own proper experiences of epidemics and at the same time would know all that had passed meanwhile--“posteris quibus integrum epidemicorum curriculum venientibus annis sibi invicem succedentium intueri dabitur.”