Thus, in England, the mean term of life is more than double what it is in Rome or Naples; and thus, while it takes 60 years to extinguish a generation in England, the brief period of 25 years completes the same work at Rome.
INTERMITTENT FEVER, OR AGUE.
Intermittent fever, more familiarly known as ague, is also a common product of air which is vitiated with effluvia arising from the soil.
That disease was much more prevalent some years ago in England than it is at present, where it is almost confined to Lincolnshire, and some of the low grounds and meadows of Kent and Essex, through which the Thames flows.
It is unnecessary to mention the symptoms of ague, as they are familiarly known. Convalescents are very liable to relapses, and many of those who have recovered from the more violent symptoms, are frequently affected, throughout the whole term of life, with very troublesome complaints, which arise from what is vulgarly known as ague cake, which is an enlargement of the spleen, an organ which lies near the stomach.
Ague is very prevalent in the West Indies, America, Holland, and other countries which are much covered with wood, are ill drained, and liable to be periodically inundated. This disease displays none of the virulence of the malignant remittent fever already noticed, yet affects vast numbers in its peculiar localities, and not unfrequently leads to mortal results.
The whole population of those fens and swamps in which ague is endemic, is generally affected at some period of existence, scarcely one person escaping.
The effluvia which produce that disease are sometimes carried to a considerable distance, and there induce their peculiar distemper; and instances are well known, where effluvia have been conveyed to high grounds, where they have attacked the inhabitants, while those in the immediate neighbourhood of the source of these vapours, have escaped for the time.
Ague is a much milder disease than the remittent fever, which springs from the same general source, viz. terrestrial effluvia, and which prevails in the East and West Indies, and on the coast of Africa.
When and where intermittent fever only is produced, it would appear that the effluvia from the soil are less virulent and concentrated, and perhaps their activity is modified or tempered by a proportionately great quantity of watery vapour combined with them in the atmosphere, by the climate of the country, and by the constitution of the people.