newspaper, and forgotten. In a few days the
doctor suffered from a well-marked paroxysm of
ague.

It has long been known that malaria is
movable by the wind; and this is quite in accordance
with what we now know of its nature. The
spores of the "ague plants," having risen and
become entangled in the mist, spores, mist
and all, are blown along together far, perhaps,
from the place where they originated. This
fact admits of considerable practical application,
especially in tropical countries, where the
wind usually blows for a long time from the
same quarter. This, too, explains the apparent
exceptions to the rule, that malaria never rises
above the ground. It is easy to see how a
volume of fog or vapour, laden with its deadly
burden of poison cells, may roll up and hang
suspended on the side of a hill, towards which
a wind blows from or across an adjacent marsh.
Instances, indeed, have occurred where the
poisonous vapour has been blown over a hill,
and deposited on the other side of it, to the
unmitigated disgust of the inhabitants, who
fondly imagined themselves secure from the
visits of their pestilent neighbour. Lancisi
tells how thirty ladies and gentlemen sailed to
Ostia, at the Tiber's mouth, on a mediæval pic-
nic. All went gloriously as a pic-nic should,
until suddenly the breeze shifted to the south,
and began to blow over a marshy tract of land
to windward of them, at a time when they were
running very close in shore. Twenty-nine of
the thirty were at once taken down with ague.
The one man who escaped had to finish his part
in the day's pleasure with sole charge of the
navigation of a boat-load of fever patients.

The poison of malaria cannot extend its
influence over even a narrow surface of water. I
have already given one instance in the quotation
from Dr. Lind. Here is another, from Sir
Gilbert Blane. Speaking of the disastrous
Walcheren expedition, when intermittents
decimated the troops on shore, he says, "Not
only the crews of the ships in Flushing roads
were entirely free from the endemic, but also
the guard-ships which were stationed in the
narrow channel between Walcheren and Beveland.
The width of this channel is about six
thousand feet, yet, though some of the ships
lay much nearer to one shore than to the
other, there was no instance of any of the men
or officers being taken ill with the same disorder
as that with which the troops were
affected." It is very possible, nay, probable,
that the vapour and its poisonous contents are
absorbed by the water over which it passes;
and if it be so, we shall need no longer to seek
an explanation of the fact that water in some
places and at various times apparently induces
the fever when drunk. Merely the drawing of
a moat around a house in a poisonous locality
is often an effectual safeguard.

Another remarkable peculiarity of the marsh
poison is its attraction towards, or adherence to,
the foliage of large leafy trees. A belt of trees
round a house in a malarious district affords
considerable protection; but it is dangerous in
such places to go under the trees: much more
dangerous to sleep under them. A friend of
mine who lately owned a large plantation in
Berbice, tells me that New Amsterdam, in that
district, is situated to the leeward of a vast and
swampy forest. The town lies right in the
track of a trade wind that blows over it through
the forest, leaving with it the putrid scent of
the marsh. Intermittent is unknown. It is,
however, an understood fact that to go into the
forest after nightfall, would be almost inevitably
fatal; also, that to cut down the trees would be
to compel the evacuation of the town.

Ague was once considered by some people a
preservative of health. Sir Thomas Watson
tells how Dr. James Sims, a London physician,
felt convinced, at the beginning of his last
illness, that he should get well if he could but
catch an ague. So down he went into the fens,
ague-hunting; but after a time he returned,
bitterly complaining that the country was
spoiled by draining, and that there were no
agues to catch. Louis the Eleventh, who had
more piety—as times went—than brains, prayed
to the Lady of Selles that in the plenitude of
her grace she would confer upon him a quartan
ague. The notion of engaging one disorder to
drive out another is so far from being itself
absurd, that—to say nothing of vaccination—it
is a part of the groundwork of the whole practice
of medicine. The chief purpose in giving
physic is to produce one unnatural condition
more or less inconsistent with the permanence
of some other unhealthy condition which is held
to be more dangerous or troublesome.

The fact that the spores of the gemiasma
produce ague, is not by any means the only instance
in which disease has been traced to a fungoid
origin. At a recent meeting of the Pathological
Society (March 3rd) Mr Simon stated on
behalf of Dr. Hallier, of Jena, that he had probably
discovered the origin of typhus, small-pox,
and four other diseases, in peculiar and definite
fungi developed in the blood. It was Dr.
Hallier, also, who last year supposed the proximate
cause of cholera to be of this nature, and
also, with all reason and demonstration of
experiment to confirm his opinion, attributed it to
the Arocystis occulta, a fungus analogous to
that producing "the blight" in rice. Dr.
Flint finds that a fungus peculiar to straw will
induce a genuine attack of the measles, though
he does not at present insist that the straw
fungus is the only source of that complaint.
Hay asthma is caused, I believe, invariably by
the inhalation of the spores of a fungus
produced during the fermentation of hay in the
process of drying. Dr. Salisbury has a paper
in the current number of the American Journal
of Science, on the fungoid origin of two other
important diseases. The pollen and volatile
principles of many actively flowering plants
produce a sensible and sometimes very severe
impression even where insensibly inhaled. In
passing through a field of flowering hops, of
lettuce, of poppies, of spotted hemlock, of