In 1816 the British garrison of English
Harbour, in Antigua, happened to be disposed
in three different barracks, one three hundred,
one five hundred, and one six hundred feet
above the level of the marshes. The dockyard
was among the marshes themselves;
and the marshes were so pestiferous, that it
often happened that a well-seasoned soldier,
coming down from the upper barracks in full
health to mount the night-guard, was seized
with furious delirium while standing sentry,
and died of yellow fever, or of something very
like it, thirty hours after he had been carried
up to his barracks. In those upper barracks,
including women and children, no fever of any
kind afflicted those who did not go down
upon duty. In the middle barracks, at a
height of five hundred feet, there occurred a
little fever, but not much worthy of notice.
In the lower barracks, every man—even of
those who did not go down to the marshes—
was attacked with remittent fever, and one
died. The Italians in the neighbourhood of
the Pontine Marshes have been taught by
experience to perch their villages on hills.

It is after the heat of summer, in autumn,
that the poison of Malaria begins to work.
Where the venom is peculiarly concentrated,
it may kill speedily, as in the case of the
sentinels just mentioned; but in temperate
climates, the poison is both weaker and
slower in its action. Many of the men who
inhaled the poison of Malaria at Walcheren,
experienced no bad effects until they had
returned to England, and perhaps lived for
some months at home. Irish harvesters
carry the poison home with them frequently
from Lincolnshire, and are attacked with
agues weeks or months afterwards in Ireland,
on the provocation of an east wind or a chill.

It is also a well-known fact, that the
inhabitants of districts subject to Malaria
become seasoned. At Walcheren, the natives
would not believe that their home was
unhealthy. In the pestilential plains of
Estremadura, the natives averred that the soldiers
were swept off by mushrooms. The seasoned
inhabitants of such malarious places are not,
however, strong or long-lived men. They are
puny, sallow, feeble, spiritless, abounding in
swelled bellies and wasted limbs. Even the
strangers, having had their dose of fever,
become seasoned to the poison. The French
general Monnet, who commanded for seven
years at Flushing, recommended therefore
that, however officers and men might demur,
garrisons should be kept stationary in
unhealthy places. He adduces the instance of a
French regiment in Walcheren, which suffered
in the second year of its residence there, only
half the sickness it had suffered in the first
year, and in the third year almost none at all.

To the statement that the dwellers in a
district subject to Malaria, though seasoned,
are unhealthy in it, an exception has to be
made in the case of the negro. "To him,''
says Dr. Ferguson, "marsh miasmata are in
fact no poison. The warm, moist, low and
leeward situations where these pernicious
exhalations are generated and concentrated,
prove to him congenial. He delights in
them, for there he enjoys life and health,
as much as his feelings are abhorrent to the
currents of wind that sweep the mountain
tops, where alone the whites find security
against endemic fevers."

There is also an exception, again in favour
of the black colour, among swamps. The
exhalations from black peat-moss are said
positively not to occasion intermittents. The
marshy tracts in many parts of Scotland and
Ireland covered with peat moss, are quite
free from fevers. The same is the case in the
instance of the Dismal Swamp, which covers a
hundred and fifty thousand acres on the
frontiers of Virginia and North Carolina.

What else we have to say about Malaria
will chiefly concern certain peculiarities of
character and habit, by a knowledge of which
we may, in case of need, perhaps be able to
protect ourselves against her deadly enmity.

Like many other bad things Malaria is most
dangerous at night; she poisons in the dark
most efficaciously. To sleep out of doors in a
malarious district is to ensure the imbibition
of the poison. A ship of war having touched
at the inland of St. Thomas, sixteen of the
crew slept several nights ashore—all of these
had yellow fever, and thirteen died. The
two hundred and eighty other men went
freely ashore in parties of twenty and thirty
during the day, returning to the ships at
night. No illness occurred among them.
Such cases might be multiplied indefinitely.
The reapers in the Campo Morto, a part of
the fatal Maremna, are allowed to sleep for
two hours at mid-day; it is then only that they
can do so without danger. All strangers are
admonished at Rome not to seek coolness by
crossing the Pontine Marshes after the heat
of the day is over. Though they are crossed
in six or eight hours, many travellers who
traversed them at night have been attacked
by violent and mortal fevers. Wise people,
therefore, in malarious districts will avoid the
night air altogether.

In the next place it should be borne in
mind that Malaria not only resembles other
evil doers in her love of night attacks, but
that she also creeps stealthily, as one who
loves the ground and tends by habit ominously
downwards. This may be one reason why
it is especially dangerous to lie down in the
night air when she is abroad. For this reason,
says Dr. Ferguson, "in all malarious seasons
and countries, the inhabitants of ground floors
are uniformly affected in a greater proportion
than those of the upper stories. According
to official returns, during the last sickly
season at Barbadoes, the proportion of those
taken ill with fever in the lower apartments
of the barracks exceeded that of the upper
by one-third, throughout the whole course
of the epidemic. At the same time it was