On Malaria . 
63 
they have been peculiarly abundant and severe during the three or four last years, 
they were in 1826 unusually destructive and numerous, having been the cause of 
a mortality, which, in England, must be deemed considerable. Every one also 
knows that agues occur in England, and very especially in certain districts, so well 
known as not to require being named : whence it cannot be doubted, that although, 
compared to France or Italy, we may be considered, comparatively, exempt from 
this cause of disease — we are very far indeed from not suffering by it; and that 
also to an extent, which, the more it is investigated, will appear the more serious. 
But to put this out of all doubt, while it serves to prove also thepowm* which 
we possess over this cause of mortality and disease, it is sufficient to review the 
history of our own country, or even of London, to be convinced that our climate 
is capable of producing malaria wherever the other necessary circumstances are pre- 
sent ; and that, in as far as we are now exempted, it has been the consequence of 
an attention directed to these circumstances. Hence the reasons, and the induce- 
ments also, to further attention of the same nature, for which it is primarily 
necessary that we should possess an accurate knowledge of them. 
How enormous and nearly incredible the diminution of agues and fevers has 
been in Lincolnshire, Essex, Kent, or generally in the fenny and mar. hy counties 
of England.since the agricultural improvement s of those lands, is matter of notorie- 
ty, since much of it has even occurred in our own days : but even in London, on 
Burnett's authority, the intermittent raged like a plague in the reign of Mary : 
while, from Sydenham, Morton, and others, to -whom we may add the testi- 
mony of Short, and more recently, the facts collected by ITeberden, the years 1658, 
1664, and those from 1667 to 1602, were year-* of a mortality from this cause, which 
could that act now as it then did, would, probably, in any one year, destroy twen- 
ty or thirty thousand persons in London alone. And this national mortality from 
fevers, from the fevers of malaria, extended even down to the year 1729, according 
to Short’s testimony — so recent are the improvements by which it has been di- 
minished. 
Here, then, it is at last proved, that the climate of England did not then exempt it 
from malaria ; and as that climate remains the same, so must this poison be still 
produced ; whatever exemption we do possess, being the consequence of having 
corrected or destroyed some of those places or soils by which it is generated ; hut we 
have not corrected them all, nor have we exterminated the disorders which we have 
diminished. This is the task which yet remains for us, and for that end it is, that I 
shall here endeavour to point out the circumstances which do produce malaria ; 
since I have, I trust, proved that it does exist among us ; too generally overlook- 
ed, and not unfrequently denied or even ridiculed, while the chief cause of this 
oversight is the error to which I here allude of misstating the cause and nature of 
the summer fevers. 
It is this error chiefly, and further, that of looking for the evidences of malaria 
in the production of intermittent solely, which prevents a correct judgment from 
being formed of the existence of this poison, and of the places producing it, though, 
in addition to the fevers of summer, I could, had 1 here sufficient space, and were 
this a proper place for it, easily show tha£ a great, many other disorders, often lit- 
tle suspected as con sequ cnees of malaria, are equally produced by it, and are equally 
the evidences of pernicious soils. But as I have no room for detailing all this evi- 
dence, I must be content with saying, that wherever I here mark any particular 
mode of land or water as productive of malaria, it is, that in some one or more 
cases of ihat variety, I have ascertained, by this very evidence, that it was present, 
and the cause of disease ; while nearly all, perhaps the whole, are further admit- 
ted or proved to he truly pernicious, by the various French and Italian physicians, 
who have bestowed on this subject an attention which has been utterly withdrawn 
from it in England. And if this detail is general, rather than special, it is not for 
want of special instances and proofs in abundance, that I have not noticed these; 
but from the recollection, that to point out the insalubrity of certain spots, might 
injure the properties, by affecting the value of those, should that which is here ad- 
duced succeed in commanding belief. 
It is plain, to commence, that there is no mystery or charm in the term marsh ; 
and that if such a tract of land can produce disease, it is because it contains vegel 
tallies growing and decomposing in a moist soil : this is the general analvsis of the 
cause; and wherever, therefore, the same circumstances occur, that spot must he, 
as to all the objects in view, a marsh, or a source of malaria. A minuter analvsis 
of the facts can scarcely be necessary, either as to the plants that grow in marshes. 
