CHAPTER X.

On the servitude of rivers--Practical knowledge of the ancients--Early Roman history a fable--The great social problems of race and climate in some measure unknown to the Romans--First mooted in the reign of Justinian--Present phases of human society--How affected by these two problems--Influence of civilization over the earth pp. 99–110

CONCLUDING CHAPTER.

Author’s theory of malaria--Has malaria a real existence?--Action of ferments on the blood--A malarious air not dislodged by storms--Quality of the air over ditches, &c.--Experiments by the Author on microscopic mollusca--Influence of chemistry over physiology--Ammonia--Its volatility and universal prevalence in the air--Its sources and action on living bodies--Danger of drainage-works during summer--Spread of plants through the air--Appearance of strange plants in a country--Conclusion--Various phases of sanitary science--laws of decomposition and composition--Results to man of a false position in nature pp. 111–128

APPENDIX pp. 129–136

ERRATUM.

Page 98, line 2 (note), should read “Hydrogen is the lightest known substance; its specific gravity is to that of air 732 to 10,000.”

AN INQUIRY

INTO

THE ORIGIN AND INTIMATE NATURE

MALARIA.

INTRODUCTION.

In addition to the wide-spread desolating epidemics which appear from time to time, mysterious in their origin, progress, and cessation or disappearance--such, for example, as the plague of Athens, the plague of London in the time of Charles the Second of happy memory, the Indian or Asiatic cholera of modern times, and the disease called influenza, a frequent visitor to Western Europe during the last half-century--there exist localities unceasingly under the influence of a poison inimical to human life. This poison, since it may be so called, is known to haunt the deltas of large rivers, and seems to be always present there; but it is found also, if we may determine its identity by the identity of its deleterious influence on men, in other and very various localities: sometimes it shows itself--and this most commonly--in marshy and fenny countries, where no large rivers exist, at other times by the banks of fresh-water lakes; now it haunts the forest, and now the open plain, where marsh and fen, swamp and decaying vegetation, seem all but absent. As the inhabitants of such localities are especially afflicted with the fevers called intermittent and remittent, it is the most natural thing in the world to ascribe to the locality itself the origin of these diseases. When, however, we attempt to generalize and assign to the same cause in a more concentrated form those terrible fevers which render tropical countries the graves of Europeans, great difficulties arise, and numerous objections, which the best of statisticians, not to mention the simply medical observer, have failed to elucidate and remove. Thus physicians are not agreed as to the identity of the poison under all circumstances, or in other words, demonstrative evidence is still wanting to prove that the cause of fever on the western coasts of Africa is identical with that which has so often in the Antilles destroyed England’s chosen troops, decimated her fleets, crippled her power, annihilated her army, as at Walcheren, and broken up the health of many a sturdy yeoman by the banks of the Scheldt, of the Thames and its tributaries.

To this poison the term malaria has been applied--a word borrowed from the Italian. This malaria is presumed, whatever it may be, to be the cause (though not exclusively), on evidence almost amounting to a certainty, of the fevers marked by intermissions and remissions; it may also be the cause of the more terrible febrile diseases called the yellow fever, the black vomit, &c., of tropical countries. On this I do not insist. As regards intermitting and remitting febrile affections, we are all but certain that to such localities as I have just alluded to, their origin may be traced, however they may originate elsewhere. A long residence in Holland and Belgium (countries supposed by many to be in an especial manner the hot-bed and active parent of malaria) has enabled me to observe, I trust in an unprejudiced manner, some facts which may have escaped the observation of others. Long resident in that land, on which perished miserably the best equipped army (an army composed of veterans) which ever, perhaps, quitted England for foreign aggression; in that land on which perished the chosen garrisons of the mighty Napoleon; on that spot where they dragged on a miserable existence, or perished in the prime of life; the writer of this essay enjoyed the best of health. Even admitting the full influence of a vigorous constitution, and an innate vitality equal to the neutralization of all malaria, a something must still be ascribed to observation leading him to avoid the hurtful and insalubrious agencies at work around him--agencies ever active, ever seeking to destroy. This information the author has thought might be useful to others, and with this view he submits it to the public.

Medical authors of the highest repute are exceedingly vague in their ideas respecting the nature of malaria; nor will it ever be otherwise until the question be taken up by the strictly scientific. Thus, Sir John Forbes says, in his “Holiday:”--“As the unknown thing which we term malaria or miasma of marshes, under certain circumstances gives rise at one time to simple ague, at another to a fatal remittent fever, &c.; and produces at times a morbid enlargement of the spleen, at others diseases of the liver, &c.; so I can imagine that some other malaria, or unknown thing or influence of local origin, may be the cause of ordinary bronchocele, of goitre of the Alps, and also of cretinism.”

From the 1st of August to December the author hunted and waded through the marshes of Belgium and Holland in quest of water-fowl; his impunity from fever may be in part ascribed to a hardy training in early life.