In this country, even so lately as half a century ago, ague or intermittent fever prevailed to a considerable extent, but is now almost unknown.
In East Lothian many of the old inhabitants remember ague as being a common disease in that county. At present it is there unknown.
In respect to this disease particularly, the health of the population of England has greatly improved, and it is well ascertained that the gratifying fact is chiefly owing to the country having been cleared of its superabundant wood, which prevented the land being readily dried, and which interfered with the due action of the winds, and to the speedy removal of water from the surface of the earth by draining, which is now so universally adopted. By draining, the water which formerly formed a receptacle for the decomposition of animal and vegetable remains, is now carried off, and with it the opportunity it afforded for the extrication of unwholesome vapours.
CHAPTER IX.
OTHER CASES OF PESTILENCE—FAMINE—UNWHOLESOME FOOD AND DRINK.
The operation of vitiated air in the production of disease is often very much assisted by the presence of other prejudicial influences.
It has been frequently remarked that one stroke of misfortune seldom comes alone, and that observation holds with striking force in reference to the causes of disease. One cause of disease produces another, which in its turn generates another, and so on, till the tendencies to, and the excitants of, pestilence, are so strong and so numerous, that whole communities are affected, one after another.
It not unfrequently happens that the predisposing source of some of the most severe visitations of the most virulent distempers, is the want of food, which generally depends on the exorbitant prices of provisions, raised either by the arbitrary regulations of rulers, or by comparative scarcity.
The total or almost total want of food is calculated to bring about, very shortly, a mortal result, from exhaustion or from sinking of the powers of the system.
When food is not withheld altogether, but is only given in sparing quantity, in an amount insufficient for the maintenance of the body in vigour, a condition of the system is induced, in which the functions are imperfectly performed, in which the blood and the various humours become universally prone to morbid change, and in which there arises a great tendency to disease of a low or asthenic character.
If, under such privation, vitiated air be present, whether arising from men in health, but uncleanly or crowded in close apartments; from the clothes, or excretions of the sick; or from terrestrial effluvia; it will give form to disease, will act as a spark amid fuel, and will shortly convert any predisposition to sickness that may exist into reality itself.