In complying with your wish that I should send you a letter exclusively
upon the subject of the disease which has committed such afflicting
ravages in our army, I shall confine myself principally to what concerns
the nature of the disorder, feeling that a minute detail of the
symptoms, and mode of treatment would not only be less interesting, but
perhaps very tedious to you.
After all that I have been able to observe, with respect to this
dreadful complaint, I think that, considering it as a malady of the West
India colonies, it may be correctly regarded as the effect of climate,
operating upon exotic bodies. It is the fever of the country—an endemial
malady, which attacks those, most severely, whose general vigour, and
whose firmness, or density of fibre offer the strongest resistance. To
look for it in ships and vessels;—to strain the eye across the ocean, in
order to fix its birth-place upon the opposite coast of the Atlantic, or
to trace its descent from the shores of the Indian seas, would be to
overlook the reality in search of a phantom! It needs no foreign parent:
the earth is its mother: its father the sun.
When Europeans first take up their residence in the West Indies, it is
usual for them, sooner or later after their arrival, to undergo an
attack of fever; which in times of peace and tranquillity, when the
“_new-comers_” are but few, is termed a “_seasoning fever_;” but in
times of war, when, from great multitudes arriving at the same period,
its destructive effects are more striking, is called a “_yellow fever_;”
but, whether denominated “_seasoning_” or “_yellow_,” or marked by any
other appellation, it is only the common bilious fever of hot climates:
and it appears under an intermittent, a remittent, or a continued form,
according to the soil and situation of the place; or the habit of body,
and other circumstances of the person attacked. In negroes and creoles
it is frequently an ague; in those who are in a degree acclimated a
remittent; and in _new-comers_ a _continued_, or, as it is commonly
termed, a _yellow_ fever; preserving, in each case, a distinct type
throughout its course; while, in other instances of its attack upon
Europeans, it shifts its form, and runs its progress with the utmost
irregularity: in proof of which I may remark that it has happened to
myself to receive newly arrived soldiers into the hospital, at the same
time, with this seasoning malady, under all the varieties of its
intermittent, remittent, and continued form: and notwithstanding each
has been differently attacked, all of them have died, in the course of
only a few days, with every symptom of the most malignant _yellow_
fever.
Nature, in her fostering care, hath endowed the human frame with the
power of accommodating itself to all the various climates upon the
habitable regions of our globe; yet hath she more expressly adapted our
organs to the particular climate in which she hath stationed us: so
constituting the nice and delicate movements of the animal machine, that
we cannot, without peril, expose ourselves to sudden or violent
transitions.
To the inhabitants of different regions is given something of
constitutional difference, which it would be difficult precisely to
define: but it belongs to a certain original conformation, creating a
difference of fibre or stamina, which more particularly befits the body
for the specific region, in which it is designed to move: yet, while
much is attributed to nature, it ought not to be forgotten that habit
follows nature very closely, in her influence upon the human frame; and
hence it is that by long residence, and similarity of pursuit, so near
an approach to this specific and original structure may be acquired, as
to promote healthy action, in a being removed to a foreign, and even to
an ungenial climate: still, this is only the yielding of a body
originally different; for the assimilation is never so complete as to be
in all respects the same. The constitution of a negro from Africa, or
the West Indies, never becomes entirely British, although he remain in
England the greater number of his days: and however much an European, by
long residence in the West Indies, be brought to resemble a creole, he
can never acquire, precisely, the constitution of a native: some marks
of original conformation will still exist, and something, even in his
general appearance, to distinguish him.
Nor is this difference of organization confined to the human subject:
other animal bodies, and also vegetables differ in their structure and
external appearance, in different climates. The wool of sheep, removed
from a northern region to the West Indies, becomes hair; and the almost
tasteless potatoe of Europe assumes a strong saccharine flavour from
tropical culture.
The influence of the atmosphere, not only in different climates, but
under its various changes in the same climate, is, at all times, and in
all countries, far greater than common opinion supposes: nor has the
attention of medical men been sufficiently directed to this
circumstance, although it is of great magnitude. Hypochondriacs, persons
subject to rheumatism, or asthma, and those afflicted with painful
thickenings of the cuticle (usually termed corns), become exquisitely
sensible of the slightest variations in the state of the atmosphere;
whence it may be concluded, that it cannot but operate, at all moments,
with a powerful effect upon the tender fibres of our delicately
organized vessels; and if, in our native region, the influence be so
considerable, must it not be infinitely more important, upon the body
being exposed to the stronger impressions of an unnatural climate,
“... where the sun, with downward torrid ray,
_Kills_ with the barb’rous glories of the day?”
Without entering more minutely into the subject, suffice it to remark,
that there appears to be a certain gradation in the tone, or firmness of
the animal fibre, as we proceed from the hotter through the more
temperate regions; not following in exact mathematical proportion, but
sufficiently manifest to form some standard for general observation;
and, perhaps, to sanction the assumption that the density or laxity of
the human fibre bears an intimate alliance with the temperature of the
climate, with respect to heat or cold; although it may be influenced,
likewise, by other circumstances; such as the dryness or moisture of the
atmosphere, the state of the soil, the manner of clothing, and the
habits pursued. In the colder regions towards the poles, the fibre is
firmer, the circulation of the fluids slower, and the secretions are
more languid; while in the warmer regions, near the equator, the fibre
is lax, respiration quicker, the circulation more rapid, and the
secretions are more copious, and more speedily performed. In order,
therefore, to fit the constitution of a polar inhabitant for a tropical
climate, or to accommodate the system of a tropical inhabitant to a
polar atmosphere, it is needful that the change should be gradual, that
the necessary density or laxity be induced, with as little risk as
possible of disorganization, and consequent dissolution[15]. Not only do
the inhabitants of cold climates suffer, on being transferred to the
tropical regions—the negroes can as ill support the change to a northern
atmosphere. They are frequently the victims of being brought to Europe:
amidst the cold of our winter, all their energies seem to be destroyed,
and their faculties benumbed: they seldom live to old age, but,
commonly, sink into marasmus, or are cut off by early consumption.
Fever, excessive heat, violent passion, or any other cause which
greatly, and suddenly hurries the circulation of the fluids, diminishes
the tone and energy of the living animal fibre, and deprives it of that
degree of firmness which is necessary to health; but, by gradually
habituating the body to the change, a high degree of increased
circulation, or a considerable diminution of the original density of
fibre may be supported, without any consequent derangement of structure:
the increased action of the vessels, the augmented velocity of the
fluids, and the subsequent laxity of fibre, induced by great heat, or
high fever, may be borne, provided they are not so sudden, nor so long
continued, as to cause disorganization.
We have many familiar examples which testify the effect of original
conformation, and the powerful influence of habit upon the animal body,
with respect to its state of health or disease. If a person accustomed
to live in the gloom of London should expose his face, for only a short
time, to the full rays of the sun, at Brighton, the skin would be
separated as if by the application of a blister; but if a hardy shepherd
of the downs were to lie upon the hills, with his face open to the broad
sun, throughout the day, not the smallest part of the cuticle would be
disturbed.
A negro, to whom the climate is congenial, can run over the hills in the
West Indies, for many hours in succession without suffering the
slightest inconvenience: but if an European of more unyielding fibre,
and only lately arrived within the tropics, were to follow him in such a
course, it would be more than probable—it would be almost certain, that,
within a few succeeding hours, a fever would complete the
disorganization, and send him to the grave.
So the fluids of a racer may be hurried violently through his vessels,
without any injury to the natural organization: but if an unpractised
horse, of a different original conformation, were to be taken from the
cart and made to gallop, with all possible speed, over a course of four
or six miles, it is probable that from the increased impulse, and the
resistance of his unaccommodating fibre, fever, disorganization, and
death would speedily ensue.
In cold or temperate climates, bulls are baited, and hares hunted, in
order that the sound texture of their fibres may be broken down, and the
muscles made tender, by their dying in the fever of increased and
violent circulation. This is a fact so well known to sportsmen, that a
hunted hare is always preferred to one that has been shot, or taken by
other means.
Epicures let their meat hang after it is killed, until the atmosphere
has effected the same purpose, by a different process, and it be made
tender by a decomposition, or partial putrefaction. But in the West
Indies, it is common to see the animal alive in the market, and to have
its joints smoking upon table the same day at dinner: it is slaughtered,
dressed, and eaten, without the flesh growing cold; yet there is no
complaint of the meat being hard or tough.
These remarks will serve to lead your attention more particularly to the
subject of climate, and to the effects of habit and original
conformation. Without attempting to enter more particularly into the
various changes, which the febrile action produces in destroying life,
or the specific mode in which these changes are effected, I may state a
few other general circumstances, which will show the application, of
what has been already said, to the subject in question, viz. the
continued, or _yellow_ fever.
Creoles and negroes are not subject to the fever in its continued, or
most malignant form: when it invades them, it appears under a remittent
or intermittent type. In these classes the original conformation, aided
by a constant exposure to the heat and atmosphere of these regions, has
established a due state of fibre, and given to the body a certain
congeniality which empowers it to continue its healthy action, amidst
all the circumstances of climate and situation.
Europeans, who have resided during a period of several years in the West
Indies, are seldom attacked with the fever in its continued form; when
it seizes them, it commonly assumes the type of a remittent. In persons
of this class, the body, from long exposure to the climate, has become
creolised, approaching to the conformation of the natives, by having the
original firmness of fibre reduced to the appropriate standard for
continuing the healthy action, under exposure to preternatural heat.
The strongest men—those of the most dense or rigid fibre are most
subject to the high degrees of the continued, or _yellow_ fever; and are
most frequently, and most rapidly destroyed by it. Women, children,
convalescents from former malady, and those who have been reduced by the
use of mercurial remedies are less frequently the objects of its attack:
and when it seizes them, it is usually milder, and less rapid in its
progress. In these classes, the state of the animal fibre, either from
original conformation, or from eventual circumstances, more nearly
approaches to that of the creoles and natives.
In North America, the inhabitants, who constantly reside in the most
southern states, are seldom attacked with the fever in its more violent,
or continued form; while those of the north-east states are destroyed by
it in great numbers: but, even in these districts, it is remarked that
the fever more readily seizes strangers from Europe, or peasants from
the interior provinces, than the natives of the towns, in which the
disease prevails. These facts are striking, and they seem to admit of
ready explanation. The inhabitants of the southern states, from being
subject to constant heat, are acclimated, and, in constitution, approach
nearly to the creoles or natives of the West Indies: but those residing
in the more northern states, although exposed to a very high degree of
heat during the summer, can never become creolised, on account of the
intervening winter, which annually renews the predisposition, and
creates a susceptibility of the disease; still, from living, during part
of the year, in excessive heat, and remaining, at all times, in the
atmosphere of their towns, the inhabitants of the place, where the
disease prevails, are, in some degree, less susceptible of the most
malignant form of the fever, than strangers from Europe, or peasants
from the inland districts, whose more dense and rigid fibre renders them
in a peculiar manner predisposed.
From these remarks, it appears that the presence of contagion is in no
degree necessary to the production of this fever. Indeed its invasion is
governed by circumstances very opposite to the known laws of contagion:
for, in proportion as the body approaches the creole structure, so is it
able to support the change of temperature, and to resist the fatal
effects of the seasoning malady. If the constitution, either from
natural organization, or from long residence, be assimilated to the
climate, _i. e._ if it be reduced to the common standard of the creoles,
there is nothing to apprehend from the disease: but if it be not, the
fever will, assuredly, make its attack, without waiting for any such
cause as contagion.
Moreover, if it can be ascertained, that certain classes of people are
most liable to be attacked, and if it can be proved that there is a
regular gradation, according as they have been more or less exposed to
the influence of climate, it must be equally unnecessary and
unphilosophical to call in the aid of a power, the application of whose
laws it were impossible to reconcile with the appearances observed. No
disease of known contagion is affected by the events which are, daily,
seen to govern the progress of the yellow fever; if, therefore,
contagion be regarded as the parent of this disease, it must be a
contagion of a very uncommon and peculiar nature; for it is a
circumstance, both singular and unprecedented, that an active and
wide-spreading contagion, prevailing in any particular country, should,
expressly, avoid the inhabitants of that country, and only lie in wait
for strangers; and, further, that should these not chance to arrive, for
many years, it would remain dormant throughout the whole period, and,
again, rush forth with undiminished vigour, the very moment when
strangers should appear! I think I might say, with the greatest
correctness, that if no person from a colder climate, should visit the
West India colonies for the space of five, ten, or any given number of
years, no instance of the yellow fever, distinct from the bilious
remittent fever of the country, would be known, during that period; yet,
if a body of men, unaccustomed to the climate, should arrive from
Europe, in the month of July or August immediately succeeding, a
considerable proportion of them would be seized, and probably destroyed
by this disease, before they had commemorated the first return of a new
year: but, can it be supposed that a most subtile and active contagion
would thus remain latent, for any specified term, amidst whole hosts of
natives, and suddenly resume all its destructive powers, as soon as a
body of more robust foreigners should come within its reach?
In England, the harvest-men and strangers, who go into the fens of Kent,
or Lincolnshire in the autumn, are more readily attacked with the
endemial fever of those counties, than the inhabitants, who constantly
dwell in the atmosphere which causes it; yet we do not learn that,
during the prevalence of any contagious malady in these districts, the
contagion cautiously avoids the men of Kent or Lincolnshire, to lie in
wait for strangers; nor, perhaps, will any physician venture to assert
that the Kentish fever is produced by infection.
It would seem more probable that the contagion, common to any particular
country, should seize the natives of that country. The plica Polonica
shuns not the people of Poland; nor the sibbens those of Scotland:
neither do the yaws spare the creoles, or the Africans. But what appears
most surprising is, that this very extraordinary contagion should not
attack the languid blacks of the West Indies; yet when it arrives in
America, that it should seize the more robust negroes of the United
States.
This is a fact, which is totally irreconcileable upon the principle of
the disease proceeding from contagion. The negro of the West Indies,
from always living in a high degree of heat, has no susceptibility: but
the negro of America acquires a predisposition from the recurrent cold
of the winter. The fibre of the one is relaxed, and yielding—of the
other dense and resisting. In the same way it is explained why the
inhabitants of Louisiana, Georgia, and the Carolinas, are less subject
to the disease, than those of Virginia, Pennsylvania, and New York. Did
the fever spread itself by contagion, we know of no cause why it should
extend its ravages to the north instead of the south; why it should
seize whites in preference to blacks; why a vigorous European rather
than a languid creole; nor, why it should avoid the sable race of the
West Indies, yet affect the negroes of North America.
It is not a law of contagion to make its attack upon the strongest
people: more commonly it assails those of tender fibre. Were any given
number of healthy men, and an equal number of children to be exposed, at
the same time, to the influence of the contagion of small-pox, measles,
or scarlatina, common observation informs us that the children would be
found to be most susceptible of the impression, and attacked in the
greatest number: but the very reverse of this would be the case if they
were to be exposed, in a similar manner, to the cause producing the
yellow fever—the men would be found to be most susceptible, and a
greater proportion of them would fall victims to the disease.
Not only does this fever invade Europeans, newly arrived in the West
Indies, in preference to creoles, negroes, and those who, by a
long-continued residence, have become acclimated; but even among these
unhappy Europeans, who happen to be susceptible, the most healthy and
robust, and, in general, those who are the earliest subjected to great
exertions, and the high degrees of temperature, are sooner seized, and
more rapidly destroyed, than those of laxer fibre, or those who have the
opportunity of becoming more gradually enured to the climate.
But the “New-comers,” if exposed to the yaws, the cra-cra, or any other
disease of decided contagion, are not found to be more susceptible than
the creoles, or the negroes: although, with regard to the bites of
musquitoes and other insects, the difference of effect upon the
Europeans, and the people of the climate, is as peculiarly marked, as it
is with respect to the yellow fever. The small puncture made in the skin
of a robust European by a musquito, or a sand-fly, frequently becomes
inflamed, tumefies, breaks into a sore, spreads into a malignant ulcer,
and, ultimately, robs the hardy son of the North of his life; while the
languid creole, or the negro, quietly lets the insect bite, without
apprehending any of this sad train of consequences.
Seeing that the fever can, unquestionably, originate without contagion,
some contend that, in its passage through the body, it generates a
matter, which is capable of producing the disease, by being diffused in
the atmosphere, and that it, thus, becomes infectious. But even in this
widest sense of the term, I cannot consider it to be either a contagious
or infectious malady; for it does not appear that, by any inherent
process, the living human body has the power of generating the _pabulum_
necessary for the production or support of this fever; or that the
disease, in its progress through the human frame, begets a poison, _sui
generis_, which may be conveyed from one person to produce the disorder
in another.
The contagious or infectious fever which proceeds from distempered human
exhalations, is a distinct malady. The yellow fever has a different
origin—is different in its symptoms, and requires a different mode of
treatment. They both have their degrees, and the mild typhus, and typhus
gravior of England are not more alike than the continued and the
remittent fever of the West Indies. Perhaps the mild, and the confluent
small-pox are more unlike: yet no one denies that either is small-pox;
or doubts that both are derived from the same cause—the same specific
virus.
If the medical attendants, and the (white) orderlies, who have been
employed in the hospitals, have suffered from the fever; still, they
have only suffered in common with the officers and soldiers, who have
not been quartered near the hospitals; and, as their proportion of duty
and fatigue has been unusually great, it were not to be expected that
they could escape better than their comrades.
The following fact seems to militate strongly against the doctrine of
the yellow fever being, originally, a contagious, or becoming, in the
course of its progress, an infectious malady, viz. that, of the
multitudes of black men and women, whom I have had occasion to see
employed constantly in the hospitals, and who have executed all the
menial duties about the sick, the dying, and the dead, I never knew even
a _single instance_ of either male or female taking the disease. Perhaps
no person will contend that this would have happened if the hospitals
had been equally crowded with patients in small-pox, measles, scarlet
fever, the jail fever, or any complaint decidedly infectious[16].
The yellow fever prevails most commonly, and most extensively, at the
decline of the wet season of the year, when the rains and the sun
irregularly alternate, and cause unsettled weather: this is also the
period when the bilious remittent, and the ague appear among the creoles
and negroes. In the midst, or at the very height of the wet season, and
during the finer dry season, the fever, in all its forms, is less
prevalent: likewise in the dry and elevated parts of the country, which
are open to the breeze, it is out of all proportion less frequent than
in low damp situations in the valleys, and about the openings of the
rivers. In North America it is principally, and almost exclusively a
disease of the low and crowded towns, seated upon the borders of the
rivers, and the bays of the sea; and is scarcely known in the inland and
more lofty parts of the country.
The great favoring circumstances, therefore, appear to be a high degree
of temperature, and a moist state of the atmosphere; to which may be
added, perhaps, the ill-chosen site of the towns: but, from the
particular season in which it spreads its ravages, and from all the
concomitances, it is probable that some miasma, or unwholesome
exhalation, may be regarded as the true _pabulum_ of the disease.
At the middle period of the wet season the ditches and canals are full,
and the brooks and rivulets fluent, so that the noxious exhalations are
neither readily formed, nor easily taken up into the atmosphere: in the
dry season, these deadly vapours are either chased away by the breeze,
or rendered inert by the intense rays of the sun: but, during the
intermediate period, at the decline of the wet season, every
circumstance tends to favor their production, and to promote their
diffusion and suspension in the surrounding air.
The fever is most readily generated in new colonies, where the land is
only partially cleared of its wood, badly cultivated, and the
half-drained soil left to exhale its noxious vapours into the
atmosphere. In the older colonies, where the forests have been long cut
down, the territory submitted to the labours of the planter, and its
surface more opened to the breeze, it is found to be less prevalent.
Examples of this are seen in the old islands of Barbadoes and Antigua,
contrasted with those of Grenada and Trinidad. The former are well
cleared, and universally tilled, and from locality as well as culture,
freely exposed to the influence of the trade-wind: in these, the disease
but seldom appears. The latter are not yet brought under general
cultivation, but are partially covered with wood, and the atmosphere is
damper, and less purified by the breeze: here, the fever frequently and
fatally rages.
In new settlements, where the land is neither well cleared, nor drained;
and particularly in the vicinity of the towns or habitations, which are
commonly placed at the lowest, and most insalubrious spots, for the
convenience of commerce, the dirty streams from the higher lands, and
often the filth of rivers, or of bays and inlets of the ocean, together
with decayed leaves, plants, and roots, and, in short, the whole
_exuviæ_ of the vegetable world collect, remain, and grow putrid; in
such situations also, the very weeds, and coarser plants, become rank
and exuberant, and, growing up only to decay, add to the fermenting
mass, which, by holding the impure waters stagnant, accumulates and
creates a noxious swamp: thus, is generated the hideous Python, who,
though often subdued by the sun’s rays, again lifts up his deadly front,
and can only be completely vanquished by the steady and persevering
industry of man.
When the effect of climate and situation shall be fully understood, and
duly estimated, the yellow fever may be no longer the scourge of our
merchants, our planters, and our armies: yet, after the long and fatal
experience the world has had, it is equally lamentable and surprising
that men should blindly continue in error, with respect to the spots
chosen for their towns and dwellings. Contrary to their better
knowledge, they prefer the convenience of commerce to the more important
advantages of health; and fix their habitations, as it were expressly,
upon the most unhealthy points of the globe. In every nation, and almost
every colony, striking examples might be selected of the strange folly
and neglect with which a circumstance of such serious magnitude is
regarded. Armies, perishing with fever, or dysentery, have been snatched
from threatened destruction, by change of station; and countries, almost
meriting the reproachful term pestilential, have been rendered
salubrious by attentions to the soil: still, on the score of health,
much remains to be done, by mankind fixing their residence where the
atmosphere is least exposed to noxious exhalations. But, alas! commerce,
and her seductive attendants, riches, dissipation, and luxury, deaden
the loud calls of Hygeia, with her more virtuous train, ease,
tranquillity, and happiness; hence it is to be feared that while man
remains ambitious, and wealth is made the public road to honors and
distinctions in society, health will continue to be only a secondary
object of his consideration. It is in the province of the physician to
expose this fatal error—to philosophy it belongs to remove it.
The fever of these regions seems, in many respects, to be governed by
the same circumstances as the endemic fever of Kent and Lincolnshire, in
England. When it attacks the natives of the country, it even assumes the
same type and symptoms: and I much suspect that if it could happen that
the temperature of these counties should continue as high as from 80° to
90° during the summer, and heavy rains should fall in July, the _yellow
fever_ would prevail in the months of August and September: but, while
the general heat of the summer shall continue below 70°, there can be no
fear of yellow fever being generated in England; and still less of its
being imported: for this is just as improbable as that the Kentish fever
should be carried off in a Scots trading vessel, and spread among the
inhabitants of Edinburgh, whose rocks, and streams, and healthy
mountains preclude its visitation.
In order to exhibit, in a more striking point of view, the similarity,
or I might say the identity of the intermittent, the remittent, and the
yellow fever of the West Indies, and to show that they are only
different degrees of the same disease, I may briefly enumerate the more
prominent points in which the resemblance is observed.
1. They run indiscriminately into each other—a quotidian, or a
remittent, sometimes becoming a malignant yellow fever; and a yellow
fever sometimes degenerating into a remittent, or an intermittent.
2. They are all connected with a derangement of the biliary system; and
a common sequel of each, is a chronic affection of the liver.
3. They all prevail, most extensively, at the same period of the year;
viz. the decline of the wet season.