which admit of a satisfactory explanation according to the principles
explained above, and consequently tend to confirm those principles. The
first point I shall notice, viz., the period of duration of the epidemic
in different places, refers merely to the communicability of the
disease, without regard to the mode of communication. The duration of
cholera in a place is usually in a direct proportion to the number of
the population. The disease remains but two or three weeks in a village,
two or three months in a good-sized town, whilst in a great metropolis
it often remains a whole year or longer. I find from an analysis which I
made in 1849 of the valuable table of Dr. Wm. Merriman, of the cholera
in England in 1832,[30] that fifty-two places are enumerated in which
the disease continued less than fifty days, and that the average
population of these places is 6,624. Forty-three places are likewise
down in which the cholera lasted fifty days, but less than one hundred;
the average population of these is 12,624. And there are, without
including London, thirty-three places in which the epidemic continued
one hundred days and upwards, the average population of which is 38,123;
or if London be included, thirty-four places, with an average of 78,823.
The following short table will show these figures in a more convenient
form:—
No. of Places. Duration in Days. Average Population.
52 0 to 50 6,624
43 50 to 100000 12,624
33} 100 and upwards { 38,123
34} „ { 78,823
There was a similar relation in 1849 between the duration of the cholera
and the population of the places which it visited; a relation which
points clearly to the propagation of the disease from patient to
patient; for if each case were not connected with a previous one, but
depended on some unknown atmospheric or telluric condition, there is no
reason why the twenty cases which occur in a village should not be
distributed over as long a period as the twenty hundred cases which
occur in a large town.
Even the duration of the cholera in a street, when compared to its
duration in the individual houses, points to the same conclusion. A
table has been published[31] in the report of the late discussion on
cholera at Munich, which shows that whilst the epidemic remained three
or four weeks in a street, it only remained six or seven days in houses
where several people were attacked. Dr. Pettenkofer remarks, that “if
the proximate cause of the disease had been generally diffused over a
certain number of streets or a certain district, and its invasion had
been opposed by individual disposition alone, one might have expected
that both the cases of disease and the instances of death would have
occurred in single houses, where many such appeared together, at similar
periods of time throughout the whole street; but, supposing that the
proximate cause of the disease was not general, but local, then it would
act in such a manner that the period of time within which the disease
would show itself in single houses would be very different from that
which was applicable to the entire street.” The local cause in a house
we know to be the illness of some individual, who, in many cases, has
newly arrived from some place where the disease was prevailing.
[Sidenote: EFFECT OF SEASON ON THE PREVALENCE OF CHOLERA.]
Each time when cholera has been introduced into England in the autumn,
it has made but little progress, and has lingered rather than flourished
during the winter and spring, to increase gradually during the following
summer, reach its climax at the latter part of summer, and decline
somewhat rapidly as the cool days of autumn set in. In most parts of
Scotland, on the contrary, cholera has each time run through its course
in the winter immediately following its introduction. I have now to
offer what I consider an explanation, to a great extent, of these
peculiarities in the progress of cholera. The English people, as a
general rule, do not drink much unboiled water, except in warm weather.
They generally take tea, coffee, malt liquor, or some other artificial
beverage at their meals, and do not require to drink between meals,
except when the weather is warm. In summer, however, a much greater
quantity of drink is required, and it is much more usual to drink water
at that season than in cold weather. Consequently, whilst the cholera is
chiefly confined in winter to the crowded families of the poor, and to
the mining population, who, as was before explained, eat each other’s
excrement at all times, it gains access as summer advances to the
population of the towns, where there is a river which receives the
sewers and supplies the drinking water at the same time; and, where
pump-wells and other limited supplies of water happen to be contaminated
with the contents of the drains and cesspools, there is a greater
opportunity for the disease to spread at a time when unboiled water is
more freely used.
In Scotland, on the other hand, unboiled water is somewhat freely used
at all times to mix with spirits; I am told that when two or three
people enter a tavern in Scotland and ask for a gill of whiskey, a jug
of water and tumbler-glasses are brought with it. Malt liquors are only
consumed to a limited extent in Scotland, and when persons drink spirit
without water, as they often do, it occasions thirst and obliges them to
drink water afterwards.
There may be other causes besides the above which tend to assist the
propagation of cholera in warm, more than in cold weather. It is not
unlikely that insects, especially the common house-flies, aid in
spreading the disease. An ingenious friend of mine has informed me that,
when infusion of quassia has been placed in the room for the purpose of
poisoning flies, he has more than once perceived the taste of it on his
bread and butter.
Dr. Farr gives the following very important information respecting the
sex of persons who died of cholera at different periods of the
epidemic.[32]
“It is worthy of remark, that at the beginning of the epidemic, the
deaths of males exceeded the deaths of females very considerably; the
numbers in the months of October, November, and December, 1848,
were,—males 612, females 493; or in the proportion of 100 to 80....
“As a general rule, when the mortality from cholera attained a very high
rate, the number of deaths among females exceeded the deaths among
males.
“In London a remarkable change was observed in the proportion of the
sexes affected in the course of the epidemic. In four weeks of October
1848, the deaths of 80 males and of 42 females by cholera were
registered; in the thirteen last weeks of the year the deaths of 258
males and 210 females were registered; and there was an excess of males
at all ages, but particularly in the ten years of age 15–25. In the
quarter ending March 1849, the deaths of males amounted to 250, of
females to 266: at the age of 25 and upwards the excess of deaths among
females was considerable. In June, at the commencement of the great
outbreak, the males again furnished the most numerous victims. At the
close of July the females died in greater numbers than the males, and
continued to do so to the end. In the week that the mortality was
highest, the deaths of 895 males and of 1131 females were returned. In
the September quarter the deaths of males under the age of 25 exceeded
the deaths of females; but after that age the proportions were
reversed.”
[Sidenote: PROPORTION OF THE SEXES WHO DIE OF CHOLERA.]
The greater part of the female population remain almost constantly at
home, and take their meals at home, whilst a considerable number of the
men move about in following their occupations, and take both food and
drink at a variety of places; consequently, in the early part of an
epidemic, when the disease only exists in a few spots, the male part of
the population is most liable to come within the operation of the morbid
poison; but at a later period of the epidemic, when the cholera is more
generally diffused, it may reach those who stay at home as readily as
those who move about; and in addition to the risk which the women share
with the men, they have the additional one of being engaged in attending
on the sick.
It is a confirmation of this view of the matter that, when the cholera
poison is distributed through the pipes of a Water Company, the above
rule does not hold good, but a contrary one prevails, owing, probably,
to females being less in the habit of drinking beer than men, and being
therefore more likely to drink water. Of the 334 deaths detailed in the
Appendix to this work (286 of them amongst the customers of the
Southwark and Vauxhall Water Company), only 147 were males, whilst 187
were females. The deaths occurred in the first four weeks of the recent
epidemic. On the other hand, out of the 229 deaths from cholera which
occurred in all the rest of London during this period, 140 were males
and only 89 females. When the mortality of the whole of the metropolis
during this period is taken together, there is a slight preponderance on
the part of the males; the numbers being,—males 287, females 276: total
563.
The deaths from cholera in England in 1849 were 53,293; of those,
14,718, or 27 per cent. of the whole, occurred in children under 15
years of age. Of the 334 deaths which are recorded in the Appendix to
this work, 127, or 38 per cent., are those of children under 15, whilst
of the remaining 229 which occurred in the rest of London during the
first four weeks of the epidemic, only 61, or 26 per cent., took place
before the age of 15,—a proportion nearly the same as in the whole of
England in 1849. The higher proportion of deaths amongst children in the
houses supplied with the impure water from the Thames at Battersea
Fields, probably arose from the circumstance that children are very fond
of drinking water in warm weather. I often heard such remarks as the
following, in making my inquiries in the south districts of London:—“My
children like water better than tea or anything else, I cannot keep them
away from the water-butt;” or, “the child that is dead used to drink a
great deal of that water, she was big enough to reach to the butt
herself.”
Dr. Guy, physician to King’s College Hospital, made a table showing the
occupations of 4,312 males, of fifteen years of age and upwards, who
died of cholera in London in the epidemic of 1848–49; together with the
ratio which the deaths bear to the living, as well as it could be
ascertained from the census of 1841. I have not room for the whole
table, but have selected the occupations which suffered most, and those
which suffered least. The following abstract of Dr. Guy’s table contains
all the occupations where the deaths from cholera equalled one-fiftieth
of the number living, and all those in which the deaths did not exceed
one in two hundred and fifty living.
[Sidenote: PROPORTION OF DEATHS IN DIFFERENT OCCUPATIONS.]
In some of the occupations which show a high relative mortality, the
number of living is too small to allow of any reliable statistical
result, and the relative mortality is probably due to accidental
circumstances quite unconnected with the occupation. In other cases,
however, the numbers are so considerable as to indicate something more
than accident. The 299 sailors, for instance, constituted one
twenty-fourth of the whole estimated number in that occupation. The 7
ballast-heavers form just the same proportion of the whole in that
occupation, and the 53 coalporters and coalheavers constituted one in 32
of those so employed. Now all those persons lived or were employed on
the river, where it is the habit to drink water drawn by pailfuls from
the side of the ship. The 67 hawkers are one in 22 of the whole number.
These persons are constantly moving about, and are in the habit of
living in crowded lodging-houses, and consequently must be extremely
liable to contract any communicable disease. Tanners nearly all live in
Bermondsey and Lambeth, supplied in 1849 with none but very impure
water, as was previously explained. The weavers probably suffered the
high rate of mortality from the crowding of their apartments in
Spitalfields, and the uncleanness of their habits.
The persons who suffered less from cholera than any other part of the
male population, are footmen and men-servants; and it is impossible to
conceive a class less exposed to the disease. They live in the best
parts of London, and go from home much less than their masters. The low
rate of mortality amongst medical men and undertakers is worthy of
notice. If cholera were propagated by effluvia given off from the
patient, or the dead body, as used to be the opinion of those who
believed in its communicability; or, if it depended on effluvia lurking
about what are by others called infected localities, in either case
medical men and undertakers would be peculiarly liable to the disease;
but, according to the principles explained in this treatise, there is no
reason why these callings should particularly expose persons to the
malady.
=TABLE XIV.=
┌───────────────────────────────────────────────────┬────────┬────────┐
│ │ No. of │ Ratio. │
│ │Deaths. │ │
├───────────────────────────────────────────────────┼────────┼────────┤
│Agents │ 12│1 in 49 │
│Bricklayers and builders │ 14│1 „ 39 │
│Cowkeepers, dairymen, and milkmen │ 8│1 „ 20 │
│Egg merchants │ 5│1 „ 6 │
│Fishmongers │ 11│1 „ 20 │
│Fruiterers and greengrocers │ 12│1 „ 28 │
│Jobmasters, livery-stable keepers │ 5│1 „ 37 │
│Oilmen │ 13│1 „ 46 │
│Paper-makers │ 2│1 „ 15 │
│Poulterers │ 3│1 „ 32 │
│Sail-makers │ 2│1 „ 30 │
│Turners │ 2│1 „ 50 │
│Ballast-heavers │ 7│1 „ 24 │
│Coal-porters and coalheavers │ 53│1 „ 32 │
│Dustmen and scavengers │ 6│1 „ 39 │
│Founders │ 10│1 „ 12 │
│Hawkers, etc. │ 67│1 „ 22 │
│Lithographers │ 3│1 „ 48 │
│Modellers │ 3│1 „ 41 │
│Polishers │ 4│1 „ 36 │
│Sailors, including Greenwich pensioners │ 299│1 „ 24 │
│Tanners │ 22│1 „ 39 │
│Weavers │ 102│1 „ 36 │
│ │ │ │
│Physicians, surgeons, & general practitioners │ 16│1 „ 265 │
│Magistrates, barristers, conveyancers, and │ 13│1 „ 375 │
│ attorneys │ │ │
│Merchants │ 11│1 „ 348 │
│Auctioneers │ 1│1 „ 266 │
│Saddlers │ 1│1 „ 250 │
│Brass-finishers │ 3│1 „ 318 │
│Coach-makers │ 16│1 „ 262 │
│Cork-cutters │ 2│1 „ 279 │
│Footmen and men-servants │ 25│1 „ 1572│
│Jewellers, goldsmiths, and silversmiths │ 6│1 „ 583 │
│Millwrights │ 2│1 „ 266 │
│Tallow-chandlers │ 2│1 „ 430 │
│Type-founders │ 1│1 „ 390 │
│Undertakers │ 2│1 „ 325 │
│Warehousemen │ 8│1 „ 472 │
│Watchmakers │ 11│1 „ 364 │
│Wheelwrights │ 8│1 „ 294 │
└───────────────────────────────────────────────────┴────────┴────────┘
[Sidenote: ABSENCE OF DRAINAGE INCREASES CHOLERA.]
There is one remarkable circumstance connected with Dr. Guy’s table. One
master-brewer died of cholera, being 1 in 160 of the trade; but no
brewer’s man or brewer’s servant is mentioned as having died of this
malady, although these men must constitute a very numerous body in
London. There must be a few thousands of them. I have, indeed, met with
the deaths of two or three of these persons, in looking over the returns
of some of the most fatal weeks in 1849; but the brewers’ men seem to
have suffered very slightly both in that and the more recent epidemics.
The reason of this probably is, that they never drink water, and are
therefore exempted from imbibing the cholera poison in that vehicle.
The great prevalence of cholera along the course of rivers has been well
known for a quarter of a century; and it meets with a satisfactory
explanation from the mode of communication of the disease which I am
inculcating. Rivers always receive the refuse of those living on the
banks, and they nearly always supply, at the same time, the drinking
water of the community so situated. It has sometimes been objected to
the propagation of the disease by the water of rivers, that the epidemic
travels as often against the stream as with it. The reply to this is,
that people travel both against the stream and with it, and thus convey
the malady from village to village and from town to town on the banks,
whilst the water serves as a medium to propagate the disease amongst
those living at each spot, and thus prevents it from dying out through
not reaching fresh victims.
The principles I have laid down afford a satisfactory explanation of the
circumstances, that absence of drainage promotes the prevalence of
cholera, and that it flourishes better on a clay soil than on primitive
rocks, sandstone, or gravel. Without drainage, the refuse of the
population permeates the ground, and gains access to the pump-wells.
Merthyr Tydvil, with 52,863 inhabitants, is entirely without drainage,
and the people derive their supply of water from pump-wells. This place
has suffered severely from cholera in every epidemic. In 1849 there were
1,682 deaths from this disease, being 234 to each 10,000 inhabitants,—a
rate of mortality as high as in Hull and certain of the south districts
of London, where the morbid poison of cholera was distributed by the
steam-engines of the water companies. The primitive rocks, sandstone,
and gravel, generally cause the purification of the water by the
separation or oxidation of organic matters, whilst clay does not exert
this salutary influence to the same extent.
Since the latter part of 1848, when I first arrived at my present
conclusions respecting the mode of communication of cholera, I have
become more and more convinced that many other diseases are propagated
in the same way.
When the plague visited this country, it was most fatal in London, York,
Winchester, and certain other towns having a river of fresh water
passing through them. It resembled cholera also in being twice as fatal
in the districts on the south of the Thames as in those on the north.
The following passage from Stow’s “Survey”, published in 1633, shows the
way in which Southwark was supplied with water about the time of the
great visitations of plague: “Southwark useth chiefly the water of the
Thames, that falls into a great pond at St. Mary Overies, that drives a
mill called St. Saviour’s Mill, the owner whereof is one Mr. Gulston.
The revenue thereof is supposed by some to be worth 1,300_l._ a year.”
[Sidenote: MODE OF PROPAGATION OF THE PLAGUE.]
Although some of the lower parts of the City were supplied with water
from the Thames, at the latter part of the sixteenth and throughout the
seventeenth century, yet the greater part of London north of the Thames
was supplied by fountains and conduits, conveying spring water from a
distance. The following quaint but poetic account of the conduits of
London cannot fail to be interesting: “As nature, by veins and arteries,
some great and some small, placed up and down all parts of the body,
ministereth blood to every part thereof; so was that wholesome water,
which was necessary for the good of London, as blood is for the good and
health of the body, conveyed by pipes, wooden or metalline, as by veins,
to every part of this famous city.... They were lovely streams indeed
that did refresh that noble city, one of which was always at work
pouring out itself when the rest lay still. Methinks these several
conduits of London stood like so many little but strong forts, to
confront and give check to that great enemy, fire, as occasion should
be. There, methinks, the water was intrenched and in-garrisoned. The
several pipes and vehicles of water that were within these conduits, all
of them charged with water, till by turning of the cock they were
discharged again, were as so many soldiers within these forts, with
their musketry charged, ready to keep and defend these places. And look
how enemies are wont to deal with these castles, which they take to be
impregnable, and despair of every getting by them,—that is, by
attempting to storm them by a close siege: so went the fire to work with
these little castles of stone, which were not easy for it to burn down
(witness their standing to this day); spoiled them, or almost spoiled
them, it hath for the present, by cutting off those supplies of water
which had vent to flow to them, melting those leaden channels by which
it had been conveyed, and thereby, as it were, starving those garrisons
which it could not take by storm. As if the fire had been angry with the
poor old tankard-bearers, both men and women, for propagating that
element which was contrary to it, and carrying it upon their shoulders,
as it were, in state and triumph, it hath even destroyed their trade,
and threatens to make them perish by fire who had wont to live by
water.”[33]
Dr. Farr makes the following remarks on the plague, in his report on the
cholera of 1848–9: “It is endemic in the Delta of the Nile, and
periodically decimates the population of Cairo and Alexandria.... It
grows gradually less fatal up the Nile, and is less frequent and
destructive in Upper than in Lower Egypt, in the high lands and in the
desert, than on the low lands on the shores of the Mediterranean.”
Speaking of Cairo, he says: “Through the midst of it passes the Great
Canal, into which the sewers are discharged over carrion, excretion, and
mud. At the yearly overflow of the Nile, its waters, filling this canal,
are distributed over the city, and drunk by its wretched inhabitants.”
The plague resembles cholera in being much promoted by crowding and want
of personal cleanliness. The natives of Gurhwal, a province in the
north-west of British India, in which the plague has been present for
the last thirty years, believe that it may be transmitted from one place
to another in articles of diet, such as a jar of ghee.[34]
[Sidenote: MODE OF PROPAGATION OF YELLOW FEVER.]
Yellow fever, which has been clearly proved by Dr. M’William and others
to be a communicable disease, resembles cholera and the plague in
flourishing best, as a general rule, on low alluvial soil, and also in
spreading greatly where there is a want of personal cleanliness. This
disease has more than once appeared in ships sailing up the river Plate,
before they have had any communication with the shore. The most probable
cause of this circumstance is, that the fresh water of this river, taken
up from alongside the ship, contained the evacuations of patients with
yellow fever in La Plata or other towns.
It was long ago observed, that dysentery was apparently propagated by
the drinking of water containing excrementitious matters.[35] The
frequent appearance of this disease in Millbank prison, when the Thames
water was used, is a confirmation of this; and Dr. Bryson has lately
related a number of instances where both dysentery and fever seemed to
be occasioned by the water of the Yangtse-Kiang, the Canton river, and
other rivers of China.[36] What very much confirms this view of the
case, is, that nearly all the patients were afflicted with great numbers
of intestinal worms (_lumbrici_); for it cannot be supposed that the
worms could proceed from malaria, miasmata, or any of the causes which
are frequently believed to occasion dysentery and fever. The eggs of the
lumbrici were no doubt contained in great numbers in the water of the
densely populated Chinese rivers.
There are many facts which indicate that one at least of the continued
fevers—the typhoid fever with ulceration of the small intestines—is also
propagated in the same way as cholera. Dr. Jenner called my attention
some time ago to an instance occurring at the village of North Boston,
Erie County, N.Y., in which typhoid fever was probably communicated to a
number of families by the contamination of the water of a well which
they used.[37] The epidemic which prevailed so extensively at Croydon
two years ago was of this character, as was verified by a Committee of
the Epidemiological Society, of which Drs. Sankey, Jenner, and A. P.
Stewart were members. Mr. Carpenter, of Croydon, has lately shown very
ably that this epidemic was connected with the pollution of the
pump-wells of the town, owing to the disturbance of the ground, and of
many old cesspools during the drainage operations of the Local Board of
Health.[38] The Board had supplied the town with good water from a deep
well in the chalk, but the population had a prejudice against it and
persisted in resorting to the water of the shallow pump-wells. In the
autumn of last year diarrhœa was very prevalent in Croydon, and Mr.
Carpenter found that this also was caused by the impure water of the
pump-wells. Nine-tenths of the people of Croydon were drinking the new
water supplied by the Board of Health, but, out of thirty-two patients
with diarrhœa who came under the notice of Mr. Carpenter, twenty-five
were drinking well-water entirely, five drank water from both sources,
and the other two could not decidedly say that they had not drank
well-water.