On Malaria. 
71 
removing or checking the influence of these. And I am sure that a more accurate 
attention, recently bestowed on fevers by practitioners, will confirm what I have 
said respecting the comparative rarity of proper contagious fevers ; if these persons 
have not yet agreed to refer them to malaria, and have not learned to discover the 
various sources whence this is produced, and which I have here been attempting to 
point out and explain. 
There is yet one important source of malaria, arising in rural situations, which I 
am bound to explain, and which will complete what I have to say of the causes of 
its diseases on shore: this is the steeping of flax and of hemp ; though with us 
the latter is rare, and the former not every common ; except in Ireland and in 
Scotland, where, from the nature of the climate, it is probably not very pernici- 
ous. Iu Germany, France, and Italy, this has been fully proved to be one of the 
most active and severe causes of fevers of this character ; as, in New York and 
elsewhere, it has been similarly proved that the same consequences, productive also 
of mortal epidemics, have arisen from the putrefaction of coffee, potatoes, the re- 
fuse of the indigo manufacture, and other similar causes. 
It remains to notice hut one case, and that an unsuspected one, — a case also 
which will probably be disputed — while T cannot help chinking that it is one of 
very extensive and serious importance : this is, bilge- water. It is remarked, in 
the first place, that sugar-ships are peculiarly subject to bad fevers, and it is well 
known that the bilge-water from this substance is the most offensive that exists. 
Further, when a ship is termed sickly at sea, it is always found, that she is what 
is called a foul ship ; of which it would be easy to produce specific examples in 
abundance from the history of the navy, were it not from the hazard of personal 
offence. And to confirm this, when it has been found that the same ship was 
sickly under one commander, and healthy under another, the cause has been equal- 
ly traced to the neglect of cleanliness. And how destructive fevers have often been 
at sea, both in the naval and the commercial service, needs not he said ; as it is 
unnecessary to point out the great loss of lives, the serious inconveniences, and, 
what is here especially necessary, the absence of every other cause of fever in snch 
a situation as the open sea. 
Now, if this class of fever is not the marsh fever, or the produce of a vegetable 
malaria, it would form a singular exception to all the analogies recently pointed 
out ; while, further, if it is not so* whence does it occur in exact proportion to the 
presence ot v egetable mat ter acted on by water, and whence especially does it occur 
in so marked a maimer in sugar-ships ? But it is generally, perhaps always, consi- 
dered as a contagious fever, and perhaps not unnaturally, under the neglect of this 
cause ; since amidst such a crowd, it is an easy conclusion that the disease is com- 
municated from one to another. Yet, if it were so, the cleanliness to which I have 
alluded would not be a prevention ; and in which, were it a contagious fever, it 
would far more often spread to the people on shore, after reaching harbour, than it 
is found to do. That there are sometimes contagions fevers on shipboard is most 
certain ; but such cases and their consequences must not be allowed to mislead us 
on so important a point as this, — since this would be to deprive us of the means of 
prevention which are in our power, mid which are as simple as they are efficacious. 
But not to dwell any longer on this case, important as it is, I cannot help think* 
ing, that when naval surgeons shall have duly considered this subject, they will 
learn to coincide in the same opinion ; and if it should prove so, then may we learn 
to prevent at sea, that which has been a most grievous evil in more ways than it is 
necessary to point out. And if ships were to be duly fumigated with sulphurous 
acid before receiving fresh crews in harbour, with such further precautions as to 
the people themselves are well understood ; and if, in addition, care was taken dai- 
ly to wash the ship, so as that the pump should bring up water as clear as the sea 
without, it is almost impossible that diseases of this character should ever make 
their appearance, or impossible, at least, that they should ever again be a cause of 
seriouR suffering. 
But I must terminate a paper which is rapidly exceeding its stipulated bounds * 
intending, in a future communication, to complete the subject, by describing what 
belongs to the propagation of malaria ; what relates to the effects of climate ; and 
what further may be done as concerns what is the real object of this paper the 
prevention or diminution of disease. 
