Chapter III: Influenzas and Epidemic Agues (5)

Influenza having continued epidemic for a few weeks in the beginning of 1848, ceased thereafter to attract popular notice in Britain during a period of more than forty years. But a certain number of “influenza” deaths continued to appear steadily year after year in the registration tables. In 1851 this number was nearly doubled, in 1855 it was more than trebled; and those two years were undoubtedly seasons (about January and February) of real influenza epidemics in Europe, recorded by several but not by English writers. A slight epidemic was described for Scotland in 1857, and one for Norfolk in 1878, neither of which seems to have influenced the registration returns in an obvious degree. After the undoubted influenza of 1855, the annual total of deaths in England set down to that cause steadily declined from four figures, to three figures, and then to two figures, standing at 55 in the bill of mortality for 1889. It is improbable that those small annual totals of deaths in all England and Wales were caused by the real influenza; the name at that time was synonymous with a feverish cold, and would have been given here or there to fatalities from some such ordinary cause. An epidemic ague was reported from Somerset in 1858[746].

The Influenzas of 1889-94.

More than a generation had passed with little or no word of epidemic influenza in this country, when in the early winter of 1889 the newspapers began to publish long telegrams on the influenza in Moscow, St Petersburg, Berlin, Paris, Madrid and other foreign capitals. This epidemic wave, like those immediately preceding it in the Eastern hemisphere, in 1833, 1837 and 1847, and like one or more, but by no means all, of the earlier influenzas, had an obvious course from Asiatic and European Russia towards Western Europe[747]. In due time it reached London, and produced a decided effect upon the bills of mortality for the first and second weeks of January, 1890, but a moderate effect compared with that of 1847, which was the first to be recorded under the same system of registration. It spread all over England, Scotland and Ireland in the months of January and February, 1890, proving itself everywhere a short and sharp influenza of the old kind, but with catarrhal symptoms on the whole a less constant feature than in the epidemics of most recent memory. At the end of February it looked as if Great Britain and Ireland had got off lightly from the visitation which had caused high mortalities in many countries of Continental Europe. But this epidemic in the beginning of 1890 was only the first of four, and less severe than the second and third. It returned in the spring and early summer of 1891, in the first weeks of 1892, and in the winter of 1893-94. To understand this influenza prevalence as a whole, its four great seasons should be compared. The following tables show its incidence upon London on each occasion:

_Four epidemics of Influenza in London, 1890-94._

1890

Annual
death-rate Deaths
Week per 1000 from all
ending living causes Influenza Bronchitis Pneumonia

Jan. 4 28·0 2371 4 530 215
11 32·4 2747 67 715 253
18 32·1 2720 127 630 281
25 26·3 2227 105 468 193
Feb. 1 21·8 1849 75 339 145
8 20·6 1749 38 369 117

1891

Annual
death-rate Deaths
Week per 1000 from all
ending living causes Influenza Bronchitis Pneumonia

April 25 21·0 1809 10 240 179
May 2 23·3 2006 37 280 241
9 25·6 2069 148 302 230
16 27·7 2245 266 352 207
23 27·6 2235 319 337 219
30 28·9 2337 310 353 189
June 6 27·0 2189 303 320 176
13 23·3 1886 249 255 166
20 23·0 1865 182 248 159
27 19·0 1538 117 151 113
July 4 16·8 1363 56 108 103

1891-92

Annual
death-rate Deaths
Week per 1000 from all
ending living causes Influenza Bronchitis Pneumonia

Dec. 26 21·9 1771 19 355 131
Jan. 2 42·0 3399 37 927 256
9 32·8 2679 95 740 246
16 40·0 3271 271 867 285
23 46·0 3761 506 1035 317
30 41·0 3355 436 844 255
Feb. 6 30·6 2500 314 492 215
13 24·6 2010 183 368 140
20 20·7 1693 79 259 137

1893-94

Annual
death-rate Deaths
Week per 1000 from all
ending living causes Influenza Bronchitis Pneumonia

Nov. 4 20·2 1695 8 191 125
11 21·4 1679 20 220 137
18 24·4 2016 22 318 228
25 26·5 2190 36 384 215
Dec. 2 27·1 2235 74 426 248
9 31·0 2556 127 491 266
16 29·1 2401 164 421 232
23 26·3 2170 147 387 203
30 23·3 1920 108 306 157
Jan. 6 24·5 2040 87 342 169
13 29·5 2462 75 490 211
20 23·7 1975 69 320 172
27 19·8 1655 41 232 152

It will be seen that the third epidemic, that of Jan.-Feb. 1892, had the highest maximum weekly mortality from influenza (506) as well as the highest maxima from bronchitis and pneumonia not specially associated in the certificates with influenza; that the second epidemic, of 1891, had the next highest maxima, and that the first and last of the four outbreaks were both milder than the two intermediate ones. All but the second, which fell in early summer, are strictly comparable as regards season (mid-winter). But although the second, in 1891, had the advantage of falling in some of the healthiest weeks of the year, it was more protracted than the original outbreak, much more fatal than it in the article influenza, more fatal also in the article pneumonia, and less fatal only in the article bronchitis. The third outbreak was not only more protracted than the first, in the same season of the year, but much more fatal in all the associated articles. As to the deaths referred to influenza (whether as primary or secondary cause), the numbers are not strictly comparable in all the outbreaks; they are probably too few in the first table, more nearly exact in the second, third, and fourth, the diagnosis having at length become familiar and the fashion of nomenclature established. It is undoubted that many of the deaths from bronchitis and pneumonia in January, 1890, were due to the epidemic; for, “while the ordinary rise of mortality in cold seasons is mainly among the very aged, the increased mortality in this fatal month was mainly among persons between 20 and 60 years” (Ogle).

While the first epidemic of the series was universal and of short duration all over the kingdom, the second and third were more partial in their incidence and more desultory or prolonged. The second, which began in Hull (and at the same time on the borders of Wales), produced the following highest weekly death-rates per annum from all causes among 1000 persons living:

_Highest Weekly Death-rates in the Second Influenza._

1891

Annual death-rate
from all
Week causes per
ending 1000 living

Hull Apr. 11 42·5
Sheffield May 2 70·5
Halifax " 2 42·1
Leeds " 9 48·5
Manchester " 9 43·6
Bradford " 16 56·7
Huddersfield " 16 54·5
Leicester " 16 44·6
Oldham " 23 50·4
London " 30 28·9
Salford " 30 45·9
Blackburn June 6 48·5

The third was heard of first in the west of Cornwall and in the east of Scotland, in the last quarter of 1891. It was in the following English towns that it produced the maximum weekly death-rates per annum from all causes:

_Highest Weekly Death-rates in the Third Influenza._

1892

Annual death-rate
Week from all causes
Town ending per 1000 living

Portsmouth Jan. 16 57·0
London " 23 46·0
Norwich " 23 44·7
Brighton " 23 60·9
Croydon " 30 47·2

These highest death-rates in the third successive season of influenza were all in the southern or eastern counties; in the latter, Colchester also had a maximum death-rate during one week of about 80 per 1000 per annum. Liverpool, among the northern great towns, appears to have had most of the third influenza. The fourth outbreak, in the end of 1893, was noticed first in the Midlands (Birmingham especially), and was afterwards heard of in the mining and manufacturing districts of Staffordshire, South Wales, Lancashire, Yorkshire and Durham, as well as in Scotland and Ireland, London, as in the table, having a share of it. The tables given of the London mortality in each of the four outbreaks, from influenza and the chest-complaints which were its most usual secondary effects, are a fair index both of the period and of the severity of the disease all over the kingdom in each of its successive appearances[748]. Everywhere the first and the fourth were the mildest, the second and third the most fatal. Deaths from “influenza” were reported from all the counties of England and Wales in the first and second epidemics, the highest rates of mortality per 1000 inhabitants in the corresponding calendar years having been in the following counties, while in all the counties the greater fatality of the second epidemic is equally marked:

1890

Cumberland ·35
North Wales ·28
Herefordshire ·28
Salop ·28
Wilts ·28
Somerset ·26
Dorset ·25
Bucks ·25

1891

Rutland 1·36
Lincolnshire 1·19
North Wales 1·09
Westmoreland 1·02
Monmouth 1·00
E. Riding Yorks ·98
Herefordshire ·98
Northamptonshire ·95

In London the entry of influenza is in the weekly bills of mortality throughout the whole period, with the exception of a few weeks; but the deaths were often reduced to unity, and there was perhaps only one occasion, besides the four great outbursts, namely the months of March and April, 1893, when cases were so numerous or so close together in households or neighbourhoods as to constitute a minor epidemic.

The type of the influenza of 1890-93 was not quite the same as on the last historical occasions. When it was announced as approaching from the Continent, everyone looked for “influenza colds”; but the catarrhal symptoms, although not wanting, were soon found to be unimportant beside the nameless misery, prostration and ensuing weakness. Some, indeed, contended that the disease was not influenza but dengue, so pronounced were the symptoms of break-bone fever[749]. Many cases had a decided aguish or intermittent character. The name of ague itself was once more heard in newspaper paragraphs, and more freely used in private talk; but, as we have long ceased to write of epidemic agues, equally as of marsh intermittents, in this country, it is not probable that there will remain any record of agues in Britain accompanying the influenzas of the years 1890-94. On the other hand the complications and after-effects of our latest influenza, more especially as affecting the nervous system, have been very fully studied[750].

That which chiefly distinguishes the influenza of the end of the 19th century from all other invasions of the disease is the revival of the epidemic in three successive seasons, the first recurrence having been more fatal than the original outbreak, and the second recurrence more fatal (in London at least) than the first. The closest scrutiny of the old records, including the series of weekly bills of mortality issued by the Parish Clerks of London for nearly two hundred years, discovers no such recurrences of influenza on the great scale in successive seasons. It is true that several of the old influenzas came in the midst of sickly periods of two or more years’ duration, such as the years 1557-58, 1580-82, 1657-59, 1678-80, 1727-29 and 1780-85. But in those periods the bulk of the sickness was aguish, the somewhat definite episodes of catarrhal fever having been distinguished from the epidemic agues by Willis in 1658, by Sydenham in 1679, by several in 1729, and by Baker, among others, in 1782. It is probable, indeed, that there were two strictly catarrhal epidemics in successive years in the periods 1657-59 and 1727-29, just as we know that, in New England, there was a catarrhal epidemic in the autumn of 1789 and an equally severe influenza, less catarrhal in type, in the spring of 1790[751]. But history does not appear to supply a parallel case to the four successive influenzas in the period 1889-94, unless we count the seasonal epidemic agues of former “constitutions” as equivalent to influenzas for the purpose of making out a series.

The Theory of Influenza.

Influenza is not an infection which lends itself to a simple theory of its nature or a neat formula of its cause. All that one can do is to indicate the direction in which the truth lies. Something broad, comprehensive, steady from age to age, telluric if not cosmic, must be sought for. Some have thought that the legendary or representative universal sickness at the siege of Troy was influenza, because it began upon the horses and dogs, as so many historical influenzas have done. But it will be sufficient to show that influenza was the same in the Middle Ages as now; for what circumstances make a broader contrast than medieval and modern? The first writer in England to mention influenza--of course not under that name--was a dean of St Paul’s in the reign of Henry II., Radulphus de Diceto[752]. He is narrating the journey to Rome of the archbishop-elect of Canterbury: his election in England was in June, 1173, he had got as far as Placentia by Christmas, whence he turned aside to Genoa, and at length reached Rome, to have his election confirmed by the pope in the nones of April, 1174. It is in the midst of this account of the archbishop’s journey, that reference is made to an influenza, otherwise known, from German and Italian chronicles, to have happened in December, 1173: “In those days the whole world was infected by a nebulous corruption of the air, causing catarrh of the stomach and a general cough, to the detriment of all and the death of many”--_universus orbis infectus ex aeris nebulosa corruptione_. What kind of infection can that be which has befallen men on both sides of the Alps within the same short time in the 12th century as in the 19th? And what kind of infection is it which has outlived so many changes in the great pestilences of mankind, has seen the extinction of plague and the rise of cholera, and all other variations, most of them for the better, in the reigning types of epidemic sickness? To have lasted unchanged through so many mutations of things, from medieval to modern, and from modern to ultra-modern, and to have become more inveterate or protracted at the end of the 19th century than it had ever been, is unique in this history. Influenza appears to correspond with something broadly the same in human life at all times. Or is it rather a thing telluric, of the crust of the earth or the bowels of the earth? Or is it perhaps cosmic, affecting men as the vintage is affected by a comet, or as if it came from the upper spheres? My belief is that we need not transcend the globe to look for its source, and that, upon the earth, we need not go deeper than the surface, nor beyond the inhabited spots. I shall come back to this from giving the history of English opinion upon it.

The best known influenzas of the 16th century all came in summer, as some of the later ones have done, so that no one thought of them as exaggerated common colds. But it happened that the influenzas observed by Willis in 1658, and by Sydenham in 1675 and 1679, came in spring or winter and in such weather as to suggest to each of those physicians that the catarrhal symptoms corresponded to the season. Robert Boyle, their great philosophical contemporary, was also a witness of one or more of these influenzas, and it appeared to him that there was more than season and weather in them.

“I have known a great cold,” he says, “in a day or two invade
multitudes in the same city with violent, and as to many persons,
fatal symptoms; when I could not judge (as others also did not), that
the bare coldness of the air could so suddenly produce a disease so
epidemical and hurtful; and it appeared the more probable that the
cause came from under ground, by reason that it began with a very
troublesome fog[753].”

I am unable to say whether Boyle was the first to apply the doctrine of telluric or subterranean emanations to influenza; he was certainly not the first to apply it to pestilences in general, for it is found in Seneca among the ancients[754], and it is clearly stated in Ambroise Paré’s essay “Sur les Venins,” having been probably a familiar notion of the sixteenth century, although a mystical and undefined one. Sydenham also, who must have discussed these questions with Boyle, referred all the more obscure or “stationary” epidemic constitutions to effluvia discharged into the air from “the bowels of the earth”: those hypothetical miasmata were for him the τὸ θεῖον of Hippocrates, the mysterious something which had to be assumed so as to explain plague, pestilential fever, intermittent and remittent fevers, the “new fever” of 1685-6, and all other epidemic constitutions which were not caused by obvious changes of season and weather. But it does not appear, and it is not probable, that he ascribed to that mysterious cause the two transient waves of influenza which fell within his own experience, those of November, 1675, and of November, 1679. On the other hand, Boyle certainly did so; he included influenza in his hypothesis explicitly; and if one examines its general terms, it will appear as if it had been made specially for influenza.

Boyle’s general expression, for both endemial and epidemic maladies, is that they are due to subterranean effluvia sent up into the air. As a chemist, and as dealing with the new knowledge then most in vogue, he assumed the sources of these miasmata to be for the most part mineral deposits in the crust of the globe, especially “orpimental and other mischievous fossiles”; but later in his writing he says:

“To speak candidly I do not think that these minerals are the causes
of even all those pestilences whose efficients may come from under
ground”; there were many mischievous fossils of which physicians and
even chymists had no knowledge, and “the various associations of
these, which nature may, by fire and menstruums, make under ground and
perhaps in the air itself, may very much increase the number and
variety of hurtful matters.”

He makes provision, also, for the hurtful matters multiplying in their underground seats, according to a principle which we know now to be true for organic, instead of mineral matters, and to be true for them above ground, or in the air, as well as under ground:

“I think it possible that divers subterraneal bodies that emit
effluvia may have in them a kind of propagative or self-multiplying
power. I will not here examine whether this proceeds from some seminal
principle, which many chymists and others ascribe to metals and even
to stones; or (which is perhaps more likely) to something analogous to
a ferment, such as, in vegetables, enables a little sour dough to
extend itself through the whole mass, or such as, when an apple or
pear is bruised in one part, makes the putrefied part by degrees to
transmute the sound into its own likeness; or else some maturative
power ... as ananas in the Indies, and medlars ... after they are
gathered, acquire (as it were spontaneously) in process of time a
consistence and sweetness and sometimes colour and odour, and, in
short, such a state as by one word we call maturity or ripeness.”

Other of Boyle’s fruitful principles (I am separating them out from amidst much other matter not specially related to influenza) are these:

“It is possible that these effluvia may be, in their own nature,
either innocent enough, or at least not considerably hurtful, and yet
may become very noxious if they chance to find the air already imbued
with certain corpuscles fit to associate with them.”

Again, the effluvia sent up into the air may pass by certain places
without causing an epidemic, because these “are not inhabited enough
to make their ill qualities taken notice of; but, more frequently,
because by being diffused through a greater tract of air, they are
more and more dispersed in their passage, and thereby so diluted (if I
may so speak) and weakened as not to be able to do any notorious
mischief.”

Again, the effluvia may not produce epidemic disease at the part of
the globe where they had emerged from under ground; an illustration of
which may be intended in the case of the Black Death, which, as he
says, came from China, yet plague is little heard of in that country,
a Jesuit, Alexander de Rhodes, who spent thirty years in those parts,
testifying that the plague is not so much as spoken of there. Again,
why are some epidemics of so short duration at a given place? Either,
he answers, because the morbific expiration from under ground had
ascended almost at once, and been easily spent; or the subterraneal
commotion which sends up the miasmata “may pass from one place to
another and so cease to afford the air incumbent on the first place
the supplies necessary to keep it impregnated with noxious exhalation;
and it agrees well with this conjecture that sometimes we may observe
certain epidemical diseases to have, as it were, a progressive motion,
and leaving one town free, pass on to another”--as notably in the case
of sweating sickness and influenza.

Lastly there are ever new forms of epidemic disease appearing, not to
count every variation of an autumnal ague “which the vulgar call a New
Disease.” Of the really new types Boyle offers the following
explanation: “Some among the emergent variety of exotick and hurtful
steams may be found capable to disaffect human bodies after a very
uncommon way, and thereby to produce new diseases, whose duration may
be greater or smaller according to the lastingness of those
subterraneal causes that produce them. On which account it need be no
wonder that some new diseases have but a short duration, and vanish
not long after their appearing, the sources or fumes being soon
destroyed or spent; whereas some others may continue longer upon the
stage, as having under ground more settled and durable causes to
maintain them.”

As a chemist, Boyle sought for the source of the pestilential emanations in underground minerals, in the new combinations of these under the action of “fire and menstruums,” in their self-multiplying power as if by subterraneous fermentation (“which many chymists and others ascribe to metals and even to stones”), and in their meeting with suitable “corpuscles” in the air of an inhabited spot wherewith to combine for their morbific effects. He assumed, also, their discharge into the air at particular spots of the globe (where they might not be directly morbific in their effects), or in a series of localities from the wave-like progress of the underground commotion; in which assumption he seems to be applying the very old idea of classical times that earthquakes and volcanic eruptions were a cause or antecedent of epidemics. Sometimes his mineral fossils were deep in the crust of the globe, touched only by the greater cataclysms; and then we might expect novelties in the forms of epidemic disease. But he does not exclude emanations from the earth’s surface proceeding more gently or insensibly.

It would be a mistake to set aside Boyle’s hypothesis of epidemical miasmata as made altogether void by his choosing strange minerals to be the source of them, and by his assuming a kind of fermentation in these inorganic matters so as to explain the continuance and spreading of the infections. Substitute organic matters in the soil for minerals in the crust of the earth, and read a modern meaning into the doctrine of underground or aërial fermentation or leavening, and we shall find Boyle’s hypothesis, especially as applied to influenza, far from obsolete. Some such adaptation of the doctrine of miasmata was made two generations later by Dr John Arbuthnot in his ‘Essay concerning the Effects of Air upon Human Bodies,’ the immediate occasion of which was the London influenza of 1733. There is nothing to note between Boyle and Arbuthnot; for Willis and Sydenham, using the Hippocratic language of “constitutions,” explained, as we have seen, the epidemic catarrhs of the spring or winter as the reigning febrile constitution modified to suit the season and weather.

Arbuthnot’s essay makes more modern reading than Boyle’s. He assumes emanations from the ground, but they are no longer from the bowels of the earth, or from deposits of strange minerals requiring earthquakes to set them free, or “fire and menstruums” to give potency to them. Of all the things that pass into the atmosphere, he makes most of the various steams and other volatile decomposing matters of men and animals; and when he brings in the earth, it is as the storehouse or receptacle of such matters, in a surface stratum no deeper than the effects of drought and rainfall could reach. While he accepts the Hippocratic doctrine of epidemic constitutions, and recognizes the air with its various organic contents as the τὸ θεῖον, the _quid divinum_ or mysterious something of epidemical causation, he does not forget that the earth is inhabited by creatures, human and other, who befoul the atmosphere by “their own steams”; again, he lays stress upon alternations of drought and moisture in the soil and subsoil as a cause of morbific emanations, not, indeed, stating the matters of fact in the very terms of Pettenkofer’s law, but assuming the presence of special organic matters in the soil as much as that does. Although Arbuthnot was hardly a serious epidemiologist, any more than Boyle, yet in the growth of opinion on the subject of morbific matters in the air, he may be said to have shifted the interest from inorganic or mineral substances and gases, to organic matters chiefly of human or animal origin, and from the deeper regions of the globe, such as only earthquakes reach, to the surface stratum of soil and subsoil which is affected by every rise and fall of the ground-water. I shall now give a few extracts, to bear out the above summary, from Arbuthnot’s essay.

“Air,” he says, “is the τὸ θεῖον in diseases, which Hippocrates takes
notice of. Air is what he means by the powers of the universe, which,
he says, human nature cannot overcome; and he lays it down as a maxim
‘that whoever intends to be master of the art of physick must observe
the constitution of the year; that the powers and influence of the
seasons (what are seldom uniform) produce great changes in human
bodies.’” He then pays a compliment to Sydenham as “endowed with the
genius of Hippocrates,” and passes on to his own analytic method.
“Many great effects must follow, and many sudden changes may happen in
human bodies by absorbing outward air with all its qualities and
contents. Nothing accounts more clearly for epidemical diseases
seizing human creatures inhabiting the same tract of earth, who have
nothing in common that affects them except air: such as that
epidemical catarrhous fever of 1728 and of this present year
[1733].... It seems to be occasioned by effluvia, uncommon either in
quantity or quality, infecting the air.... It is likewise evident that
these effluvia were not of any particular or mineral nature, because
they were of a substance that was common to every part of the surface
of the earth: and therefore one may conclude that they were watery
exhalations, or, at least, such mixed with other exhalable substances
that are common to every spot of ground.”

In his account of the qualities and contents of the air, he enumerates
them, not so much as detected in the air on analysis, but as having of
necessity passed into it, and in some instances been deposited again
from it, as in strange dews. One class of substances that pass into
the air are the oils, salts, seeds and insensible abrasions of
vegetables. Also all excrements and all the carcases of animals vanish
into air. Another ingredient of the air is the perspirable matters of
animals, the amount of which for human beings he works out by a
curious calculation of a column of their own steams raised so many
feet high in so many days. Perhaps there are insects in the air
invisible to human eyes: one may observe, in that part of a room which
is illuminated with the rays of the sun, flies sometimes darting like
hawks as if it were upon a prey. Some have imagined the plague to
proceed from invisible insects: this system agrees with many of the
appearances in the progress or manner of propagation of that disease,
but is altogether inconsistent with others. Air replete with the
steams of animals, especially such as are rotting, has often produced
pestilential fevers in that place: of which there are many instances.

But why should certain years or seasons have a pestilential
atmosphere, for example the season of the catarrhous fever of 1733?
There had been, he says, an unusual drought for these two years past,
the best estimate of the dryness of the surface of the earth being
taken from the falling of the springs, “the consequence of which has
been unusual diseases amongst several animals, and a great mortality
amongst mankind. It is true, this did not happen during the dry
weather.... The previous great drought must have been particularly
hurtful to mankind. Great droughts exert their effects after the
surface of the earth is again opened by moisture, and the perspiration
of the ground, which was long suppressed, is suddenly restored. It is
probable that the earth then emits several new effluvia hurtful to
human bodies: this appeared to be the case by the thick and stinking
fogs which succeeded the rain that had fallen before.”

Arbuthnot knew the progress of the influenza of 1732-33. Its worst week in London was from the 23rd to the 30th January, 1733; but he tells us that it had been at a height in Saxony from the 15th to the 29th November, 1732, had been earlier in Holland than in England, earlier in Edinburgh than in London, in New England before Great Britain. Again, it appeared in Paris in February, somewhat later than in London, and in Naples in March. This progress, he says, was often against the wind. Nor does he assume a progressive infection of regions of atmosphere. The effluvia, he says, were of a substance that was common to every part of the surface of the earth; they were exhalable substances that were common to every spot of ground; the excessive drought of two years, followed by heavy rains in the end of 1732, is also assumed to have been common, for, in Germany and France, especially in November, 1732, the air was filled with frequent fogs. It is clear that Arbuthnot traced the universality of influenza, the uniform symptoms of which he recognized, to certain conditions of soil and atmosphere common to all the countries visited by the epidemic.

Throughout the rest of the 18th century there were numerous and varied experiences of influenza, in summer and winter, spring and autumn, coming up from the south as if from Africa, or from the east as if from Central Asia, or appearing in America sooner than in Europe--experiences which made a theory of the disease difficult. Some inclined to Arbuthnot’s view of unusual seasons and weather producing the same effects everywhere; others favoured the hypothesis of contagion from a remote source, which might be China or might be some other territory. Geach, a surgeon at Plymouth who was a Fellow of the Royal Society, actually went back to the astrological cause, pointing out that Jupiter and Saturn were in a certain conjunction during the influenza of 1775. The only elaborate theory of the strange disease that calls for notice, besides those of Boyle and Arbuthnot, is that of Noah Webster, the famous lexicographer of Hartford, Connecticut.

While Webster was a journalist in New York about the years 1794-6, the subject of yellow fever, which was then of great practical moment, set him reading and speculating about pestilences in general. Writing to Priestley, he said that in the course of his inquiries he found the American libraries ill supplied with books[755]; but he certainly made diligent and skilful use of his literary materials, and produced in his ‘Brief History of Epidemic and Pestilential Diseases,’ a work which was better than any before it in the chronological part, and remains to the present time unique in its philosophical part for the boldness of its generalities[756]. He saw that influenza was the crux of epidemiology, and paid special attention to it.

In looking for the antecedents of influenza, he kept in view the greater telluric changes and convulsions, such as earthquakes and volcanic eruptions. He did not regard these as the cause of influenza, but as the index of some hidden cause to which both they and the universal catarrh were due.

“It is probable to me,” he says, “that neither seasons, earthquakes,
nor volcanic eruptions are the causes of the principal derangements we
behold in animal and vegetable life, but are themselves the _effects_
of those motions and invisible operations which affect mankind. Hence
catarrh and other epidemics often appear _before_ the visible
phenomena of eruptions and earthquakes[757].” As to influenza, he
found “reason to conclude the disease to be the effect of some access
of stimulant powers to the atmosphere by means of the electrical
principle. No other principle in creation, which has yet come under
the cognizance of the human mind, seems adequate to the same effects.”

And again: “It is more probable that it is to be ascribed to an
insensible action of atmospheric fire, which is more general and
violent about the time of eruptions, and which fire is probably
agitated in all parts of the globe, although it produces visible
effects in explosions in some particular places only.” It is due to
Webster to give his reason for preferring a physical force to an
organic poison: “If a deleterious vapour were the cause, I should
suppose its effects would be speedy, and its force soon expended, the
atmosphere being speedily purified by the winds. But if stimulus is
the cause, it may exist for a long time in the atmosphere, and the
human body not yield to its force in many weeks or months. This would
better accord with facts. For, although diseases appear soon after an
earthquake, yet the worst effects are often many months or years
after[758].”

Dr Blagden also saw a difficulty in “the prodigious quantity of matter required in the air to infect the space not only of the Chinese land, but to a hundred leagues of the coast, or, as in this instance [1782] all Europe and the circumjacent sea,” and was accordingly driven to Arbuthnot’s view of an origin in the unusual weather of each locality.

Webster drew up a chronological table of influenzas in either Hemisphere, with the volcanic eruptions, earthquakes, comets, etc., to suit[759]. A few instances from near the beginning may serve as samples:

1647. First catarrh mentioned in American annals, in the same year
with violent earthquakes in South America, and a comet.

1655. Influenza in America, in the same year with violent earthquakes
in South America and an eruption of Vesuvius. It began about the end
of June.

1658. Influenza in Europe after a severe winter: the summer cool.

1675. Influenza in Europe while Etna was still in a state of
explosion: the winter mild.

1679-80. Influenza in Europe during or just after the eruption of
Etna: the season wet: a comet.

1688. Influenza in Europe in the same year with an eruption of
Vesuvius, after a severe winter, and earthquakes: it began in a hot
summer.

1693. Influenza in Europe in the same year with an eruption in Iceland
and great earthquakes: the season cool.

1697-98. Influenza in America after a great earthquake in Peru: a
comet the same year: the winter severe.

In most instances the region of the earthquake is not specified in the table; but it is sometimes named in the text of the annals under the respective years. Volcanoes are on the whole made more of than earthquakes, Webster’s object being to find evidence of “electrical stimulus,” and not of material miasmata discharged into the air. Etna and Hecla are much in request. Any earthquake suits, as if “earthquake” and “volcano” were like algebraic symbols, always _a_ and _b_, and never anything but _a_ and _b_, “influenza” being always _x_. One begins to realize the difficulties of the volcano or earthquake theory of influenza on turning to Mallet’s Catalogue of Earthquakes[760]. Here, indeed, is an embarrassing choice between China and Peru, Asia Minor and North Africa, Portugal and Sicily or Calabria, Iceland and Jamaica, the Azores and the Philippines, Caracas or Acapulco and Valparaiso, Hungary and Savoy, Kamtschatka and Amboina; between earthquakes great and small; between earthquakes and volcanoes. Any influenza year might be suited with one or more earthquakes, perhaps in either Hemisphere; but there are some long clear intervals between the greater influenzas in Europe, for example the interval from 1803 to 1831, which seem to occupy as many pages of the catalogue of earthquakes as the years wherein influenzas came thickest, for example from 1729 to 1743, or from 1831 to 1847.

None the less, Webster, like Boyle, obeyed a true impulse when he looked for the cause of influenzas in something telluric, occasional, phenomenal. A wave of influenza comes up unexpectedly from a particular point of the compass, passes quickly over many degrees of latitude and longitude, lasting a few weeks at any given place, disappears in the distance, and does not return again perhaps for a whole generation. Influenza has the qualities of suddenness, swiftness, transitoriness; it has a certain sameness in its symptoms; it can be identified as certainly in the brief phrases of medieval chronicles as in elaborate modern descriptions; it has had no season for its own, as plague and cholera have had the summer and autumn, but has reached a height in Europe sometimes in midsummer, sometimes in midwinter. No other epidemic malady can compare with it in these respects; all the rest seem to have been provoked more or less by the turns and changes in human affairs, some being of a medieval colour, others of a modern, each in its own way admitting of explanation from unwholesome living, or from famine, or from over-population, or from something more recondite but still within the sphere of things insanitary in an intelligible sense. Other plagues besides influenza were, it is true, once reckoned mysterious, or associated in the popular mind with earthquakes and comets. But several such plagues have disappeared from among us, while their alleged causes, the earthquakes or comets, continue as before. Influenza alone returns at intervals as of old, untouched by civilization, by sanitation, by the immense differences between medieval and modern, making the same impression upon England in the year 1890 as it did in 1173, or 1427, or 1580, or, if changed at all, then changed for the worse inasmuch as the epidemic came back more severely in 1891, and still more severely in 1892. It is not surprising that for such a disease something telluric or even cosmic should have been assigned as the cause, something as occasional as itself, phenomenal, if not cataclysmic. It may be proper, therefore, that we should try over again the philosophic generalities of Boyle, Arbuthnot and Webster, peradventure a combination of them may yield a true theory. From Boyle we may take the great principle of a progressive infection through regions of air (or leagues of ground), which was expressed once for all by Lucretius in the sixth book of the ‘De Rerum Natura’:

... atque aer inimicus serpere coepit;
Ut nebula ac nubes paulatim repit, et omne
Qua graditur, conturbat et immutare coactat;
Fit quoque ut in nostrum quum venit denique coelum
Corrumpat reddatque sui simile atque alienum.

From Arbuthnot we may take the organic source and nature of the influenzal miasmata, and the association with changes in the level of the water in the soil. From Webster we may take the idea that the historic influenzas, having been sudden, occasional or phenomenal, must have had phenomenal causes somewhere in either Hemisphere. Instead of sketching a theory in the abstract, and safeguarding it by following all its ramifications, I shall proceed by the way of instances, choosing them so as to bring out particular points in order.

The only generality which may be indicated at starting is one that has presented itself time after time in the foregoing history, namely that there is something more than accident in the association between epidemics of influenza and epidemics of ague. So close was this association in former times that both the influenza and the widely prevalent ague were included together under such names as “the new ague,” “the new fever,” “the new distemper.” As late as 1679, Morley did not distinguish the epidemic of influenza from the epidemic agues in the midst of which it was set, although the distinction was real, and was actually made by Sydenham on that occasion, as it had been made by Willis and in a manner by Whitmore on the occasion immediately preceding, and as it was made by everyone on the last great occasion when an influenza made an interlude among epidemic agues in the year 1782. It has often been suspected that influenza was related to some other infection: at one time it was taken for a volatile emanation of plague, in our own time it has been regarded as a volatile emanation of Asiatic cholera. In a wider historical view the question may arise, whether the real relation is not rather to those remarkable agues which have been epidemic in company with influenza when there was no plague and no cholera.

I come now to certain influenzas, as illustrating particular points of theory, in order.

I.

It is probable that Webster’s theory of influenza as related to earthquakes and volcanoes, first published in 1799, was suggested to him by a communication to the Royal Society on the volcanic waves seen at Barbados on the 31st of March, 1761, and on the epidemic of influenza thereafter ensuing all over the island. At Bridgetown, in the afternoon of the 31st of March, 1761, the water in the bay and harbour ebbed and flowed to the extent of eighteen inches or two feet at intervals of eight minutes, and continued to do so for the space of three hours, the oscillation regularly decreasing till night when it was no more observable. These tidal waves were due to volcanic upheavals somewhere; and it was found that the centre of disturbance had been in the Atlantic near the coast of Portugal, and the time some hours earlier than the waves were felt at Bridgetown. The Barbados chronicler proceeds:

“It is very remarkable that since that time the island has been in a
very deplorable condition, having suffered under the severest colds
that have been ever known. The distress has been so general that I may
venture to assert (with confidence) that nineteen twentieths of the
inhabitants of the island have felt the effects of the contagion; and
to some it has been repeated several times. It has puzzled all the
adepts in pharmacy to find out the cause and cure of it. One
favourable circumstance has attended it, viz. few have died with it.
The Leeward Islands have not escaped, it having raged there more
violently and more fatal. His Majesty’s ships have severely felt the
effects of it, some of them not being capable of keeping the seas for
want of men fit for service. This happening at a season of the year
remarkably the healthiest, makes it the more surprising[761].”

This is as good an instance as we shall find, of explaining something sudden, swift, and phenomenal, by something else sudden, swift, and phenomenal, in a purely empirical way and without pausing to ask whether the latter could have been a _vera causa_ of the former. That the influenza came to Barbados in the wake, as it were, of the volcanic waves, had been a common subject of talk among the residents; and that common opinion of the colony had found expression in the paper sent to the Royal Society. The influenza was not only in Barbados, in the Leeward Islands, and in the ships on the West Indian Station, but also in New England and “over the whole country” of the North American Colonies. Dr Tufts, of Weymouth, New England, wrote to Webster that “it began in April, and in May ran into a malignant fever which proved fatal to aged persons. It spread over the whole country and the West India Islands[762].” It was not until some nine months after that influenza appeared in Europe, at first in the east of that continent,--Hungary, Vienna, Breslau, Copenhagen--in February and March, 1762, in central Germany and Scotland in April, in London about the first of May and all over England and Ireland thereafter, but not in France until June and July.

Precisely the same order was followed by the influenza twenty years after: it began in North America in March, 1781, and, says Webster, spread over that continent; it appeared in the East Indies in October and November, 1781, and on the eastern confines of Europe in January, 1782, having been traced from Tobolsk, made a slow progress westwards, and was at its height in London about the end of May or beginning of June. Assuming, says Webster, that the American influenza of 1781 had been continuous with the European of 1782, it must have “passed the Pacific in high northern latitudes,” traversed Siberia and Tartary, and so reached Russia in Europe. In like manner, if the European influenza of 1762 were continuous with the American of 1761, it must have made the circuit of the globe in the same order, as if it were following the first impulse of the volcanic waves across the Atlantic from the coast of Portugal westwards, and so round the earth until it came back to Europe on its eastern frontier. So much may be fairly advanced on the ground of a particular set of facts. But then there were many other facts, both in 1761-62, and in 1781-82. Meanwhile let us take another instance of volcanic waves felt at Barbados six years before, on the same afternoon as the great earthquake of Lisbon.

II.

At Bridgetown, on the 1st November, 1755, Dr Hillary saw the peculiar flux and reflux of the water in the harbour from 2.20 p.m. to 9 p.m. and pronounced that there must have been an earthquake somewhere. The waves came at first at intervals of five minutes, and at last at intervals of twenty minutes. The day was calm, and the ships in the bay were not touched; but small craft lying in the channel over the bar were driven to and fro with great violence. There was no motion of the earth, and no noise. The distance from Lisbon was 3400 miles, the vibrations having taken seven and a half hours to reach Barbados. The one notable effect in the harbour of Bridgetown was that the water flowed in and out with such a force that it tore up the black mud in the bottom of the channel, so that a great stench was sent forth and the fishes caused to float on the surface, many of them being driven a considerable distance on to the dry land where they were taken up by the negroes[763].

It so happened that there was an epidemic catarrh prevalent at that very time all over the island of Barbados, chiefly among children, few or none of whom, white or black, escaped it. It had begun in October, says Hillary[764] (who chronicled the epidemiology very exactly), and continued into November, so that it both preceded and followed the great convulsion in the bed of the Atlantic, which destroyed Lisbon and tore up the mud in the harbour of Bridgetown, disengaging a great stench therefrom and poisoning the fish. Webster’s theory of a relation between earthquakes and influenzas provides for such discrepancies in the dates of each: it is probable, he says, that seasons, earthquakes and volcanic eruptions are themselves the effects of those motions and invisible operations which affect mankind, so that catarrh and other epidemics often appear _before_ the visible phenomena of eruptions and earthquakes. In like manner, the chronicler of the earthquake of Lisbon in the _Philosophical Transactions_ drew attention to the fact that there had been a remarkable drought for several years before, and that some of the springs near Lisbon were actually dried up at the time. That droughts precede earthquakes is perhaps the most instructive generality that has yet been reached as to the cause of the latter.

Let us see, then, whether any such remote antecedents, in a possible relation to the influenza epidemics, hold good for the island of Barbados. Hillary’s chronicle is sufficiently full to let us answer the question.

Following the seasons and prevalent maladies backwards from the
influenza of children in October-November, 1755, we find a catarrhal
fever all over Barbados in February of the same year, which “few
escaped having more or less of.” The immediate precursor of that
influenza had been a very definite constitution, eighteen months long,
of a “slow nervous fever,” from February, 1753 to September, 1754,
which corresponds in every respect to the “remittent” fever of nearly
the same period in England and Ireland, described by Fothergill,
Rutty, Huxham and Johnstone, and to the famous Rouen fever described
by Le Cat. Hillary is clear that the “slow nervous fever” was not seen
again so long as he remained in the colony (1758). Just before it
began, there had been an influenza so general in December, 1752, and
January, 1753, “that few people, either white or black, escaped having
it,” and that, in turn, was preceded by a season of agues, which, says
Hillary, “are never seen in Barbados now [1758], unless brought hither
from some place of the Leeward Islands.”

So many influenzas in Barbados, and so many things possibly relevant to them among their antecedents. So also in New England, the influenza which seemed to follow the earthquake along the coast of Portugal on the 31st of March, 1761, had the same remittent and intermittent fevers among its antecedents.

In the winter and spring of 1760-61 there had been much fever in New
England, which was believed to be malarious. Webster, however, says:
“There is no necessity of resorting to marsh exhalations for the
source of this malady. The same species of fever [as at Bethlem]
prevailed in that winter and the spring following in many other parts
of Connecticut where no marsh existed. In Hartford it carried off a
number of robust men, in two or three days from the attack.... In
North Haven it attacked few persons, but everyone of them died. In
East Haven died about forty-five men in the prime of life, mostly
heads of families. The same disease prevailed in New Haven among the
inhabitants and students in college.” In Bethlem the sickness began in
November, 1760, and carried off about forty of the inhabitants in the
winter following. This was the fever, generally reckoned malarious,
which preceded the influenza of April and May, 1761[765].

III.

The next great influenza, twenty years after, which was in America in the spring of 1781 and in Europe in the winter and spring following, will repay the same kind of scrutiny. There had been influenza here or there in Europe since the beginning of 1780, but no great epidemic of it; and in England, as elsewhere, there had been epidemic agues and dysenteries since that year, or the autumn before. The epidemic agues became worse in England in 1783, 1784, and 1785, appearing in places which had never been thought malarious. The whole period from 1780 to 1784 was remarkable for hot and dry summers and great earthquakes. Italy and Sicily were troubled by earthquakes to an unusual extent in 1780, 1781, 1782, and 1783; they were so frequent in 1781 that the pope ordered public prayers. The great earthquake of the period was in Calabria at half an hour after noon of the 5th of February, 1783, about six months after the great influenza of the period was over. Sir William Hamilton, the British ambassador at Naples, visited the numerous scenes of the earthquake in Calabria and Sicily in the first fortnight of May, 1783, and sent to the Royal Society an account of what he saw. At several places he found fever epidemic, part of it from the overcrowding and filth of the temporary barracks in which the people were living, part of it malarious from the damming of water by changes in the river beds. At Palmi the spilt oil mixed with the corn of the overthrown granaries, and the corrupted bodies, had a sensible effect on the air, which threatened an epidemic; at the village of Torre del Pezzolo an epidemical disorder had already manifested itself[766].