During the prevalence of strong north, north-east, and north-west winds, blowing with considerable violence the currents in mines are reversed—for, instead of gases issuing from the fissures and crannies, currents of atmospheric air pour into them. These currents may be felt with the hand, and the ear can detect the rushing sound; a flame applied to a fissure is immediately drawn in, shewing the direction of the current. These facts illustrate the influence which the state of the atmosphere has upon terrestrial vapours.
As has been already observed, the exhalations from the soil obtain different names from the effects they are wont to produce. When they produce intermittent fever or ague, they are termed marsh miasms. When they produce the various forms of malignant fever, such as the yellow, the bilious fever of India, and the coast of Africa, simply pestilential effluvia—and when they induce general bad health and degeneracy of the inhabitants of a country, they are styled malaria, an Italian expression signifying bad air.
As the subject appears one which may interest the general reader, it is proposed to add a few observations on the diseases which are caused by air vitiated with effluvia from the soil.
CHAPTER VII.
MALIGNANT FEVER.
A vast proportion of the most virulent diseases to which the human race is subject in almost all parts of the world, but more especially in tropical regions, is produced by the action of effluvia arising from decomposing dead animal and vegetable matter on the surface of the earth, and incorporated with the soil. These effluvia are the immediate instrument by which thousands of our fellow men are annually deprived of existence, the career of the young and the robust is abruptly stopped, never again to be renewed. Malignant fever is the disease, by which death is occasioned from these effluvia; and this fever assumes forms, characters, and titles, various and manifold. It ravages in almost every country within the tropics, and in many situations it annually commits the most dreadful havoc—cutting down so rapidly that the ordinary forms of burial cannot be observed. Whole communities suffer, the inhabitants of a particular tract of country are sometimes almost extirpated, and to visit some countries is almost to incur death from pestilence, so near to certain is attack, and its destructive character is so uniform.
The average duration of life in many countries is extremely low, chiefly on account of the wasteful career of that scourge, under its various characters and designations; and it is not saying too much that there the number of deaths is four times as great as occurs in our own happy country.
In those regions in which malignant fever prevails so much, almost every inhabitant at one period of his life, sooner or later, is afflicted with it. If he survive he is more fortunate than thousands of those who lived beside him; but his health is often deteriorated, he is often deprived of that vigour and elasticity both of mind and body, which spring from a sound constitution, and he not unfrequently lingers under the sufferings of chronic disease till his life is gradually though slowly exhausted; unless, indeed, as often happens, it is suddenly terminated by a fresh attack of the active pestilence.
“Almost every territory in which it (malignant fever) has committed its ravages has given it a new name. It is as gorgeously arrayed with titles as the mightiest monarch of the East. From the depredations it has committed in the West Indies, and on the American coast, it has been called the St Domingo, Barbadoes, Jamaica, and American fever; and from its fatal visitations on the Guinea Coast, and its adjoining islands, the Bulam fever. In British India it is distinguished by the name of Jungle fever, and still farther to the east by that of Mal de Siam. Nearer home, in the lowlands of Hungary, and along the south of Spain, it is called the Hungarian or the Andalusian pestilence. From its rapid attack on ships’ crews, that are fresh to its influence, the French denominate it Fievre Matelotte, (fever of sailors) as the Spanish and Portuguese call it vomito Prieto or black vomit, from the slaty or purplish and granular suburra (grounds) thrown up from the stomach in the last stage of the disease; while, as its ordinary source is moist lands, it has frequently been named Paludal Fever.”[[6]]
[6]. Good’s Study of Medicine, vol. ii. p. 145.
This fever is severe with new settlers in these countries. Persons visiting places in which it is endemic, during its severity almost necessarily suffer, but sometimes they escape with a slight attack, in which case they are said to have had a “seasoning fever.” The pestilential vapours may be carried to a great distance, by winds and currents. Instances have already been given where districts are immediately rendered unhealthy upon the visitation of a wind which has passed over an unhealthy swamp at a distance. Many instances are also well known where ships, riding at the distance of a league from an unhealthy coast, have had their crews affected with the distemper, on the vapours being sent among them by the wind coming off that direction. The British navy is, alas, too familiar with instances of ships being visited by that pestilence when lying off the coast of Africa, where, too, no direct communication had been maintained. The most appalling mortality occurs in these cases; it is not unusual during the short period a ship remains on that station for the whole officers and crew to be swept away in one general tide of death, and it not unfrequently happens that, after the short space of three years, the ordinary time of service, that when a ship returns to England, she has not a hand on board she carried out—but is manned with a crew that has succeeded one which had, in its turn, taken the place of that which danced in joy, and looked all gallantry, only a few short months before, when with hearty huzzas they left their native land, and committed themselves to their bark and to the buoyant billows. At the time of the expedition to Walcheren a disastrous state of health prevailed among the soldiery in Holland, in consequence of vitiated air and other forcible adjuvants;—the pestilential vapours which arose from the soil were borne by the winds to the ships riding at a distance, and there fever failed not to manifest itself with its usual severity.