In leaving a place infected by miasmata, care should be taken not to expose the body to great cold, heat, or fatigue, for eighteen or twenty days, lest they should excite the dormant seeds of the disease into action.
But where flight is not enforced by law, or where it is not practicable, or preferred, safety should be sought for in such means as reduce the preternatural tone and fulness induced in the blood-vessels by the stimulus of the miasmata, and the suppression of customary secretions. These are,
1. A diet, accommodated to the greater or less exposure of the body to the action of miasmata, and to the greater or less degrees of labour, or exercise, which are taken. In cases of great exposure to an infected atmosphere, with but little exercise, the diet should be simple in its quality, and small in its quantity. Fresh meats and wine should be avoided. A little salted meat, and Cayenne pepper with vegetables, prevent an undue languor of the stomach, from the want of its usual cordial aliments. The less mortality of the yellow fever in the French and Spanish West-India islands than in the British, has been justly attributed to the more temperate habits of the natives of France and Spain. The Bramins, who live wholly upon vegetables, escape the malignant fevers of India, while whole regiments of Europeans, who eat animal food, die in their neighbourhood. The people of Minorca, Dr. Cleghorn says, who reside near gardens, and live chiefly upon fruit during the summer, escape the violent autumnal fever of that island. The field negroes of South-Carolina owe their exemption from bilious fevers to their living chiefly upon vegetables. There is a fact which shows, that not only temperance, but abstinence bordering upon famine, has afforded a protection from malignant fevers. In a letter which I received a few months ago, from the Rev. Thomas Hall, chaplain to the British factory at Leghorn, containing an account of the yellow fever which prevailed in that city, in the summer and autumn of 1804, there is the following communication. “Of the rich, who live in large airy houses, there died but four persons with the fever. Of the commodious, who live comfortably, but not affluently, there died ten. Of the poor, who inhabited small and crowded rooms, in the dirty and confined parts of the city, there died nearly seven hundred. But of the beggars, who had scarcely any thing to eat, and who slept half naked every night upon hard pavements, not one died.” From the reduced and exhausted state of the system in these people, they were incapable, if I may be allowed the expression, of the combustion of fever. Persons reduced by chronic diseases, in like manner, often escape such as are acute. Six French ships of the line landed 300 sick, at St. Domingo, while the yellow fever prevailed there in the year 1745, and yet no one of them was infected by it[15].
Where the body is exposed to miasmata, and a great deal of exercise taken at the same time, broths, a little wine, or malt liquors, may be used with the fruits and garden vegetables of the season, with safety and advantage. The change from a full to a low diet should be made gradually. When made suddenly, it predisposes to an attack of the disease.
2. Laxative medicines. Hundreds, perhaps thousands, of the citizens of Philadelphia were indebted for their preservation from the yellow fever to the occasional use of a calomel pill, a few grains of rhubarb, or a table-spoonful of sweet, or castor oil, during the prevalence of our late pestilential fevers. Even the air of Batavia has been deprived of its poisonous quality, by means of this class of medicines. A citizen of Philadelphia asked a captain of a New-England ship, whom he met at that island, how he preserved the whole crew of his ship in health, while half the sailors of all the other ships in the harbour were sick or dead. He informed him, that it was by giving each of them a gentle purge of sulphur every day.
3. A plentiful perspiration, or moderate sweats, kept up by means of warm clothing and bed-clothes. The excretion which takes place by the skin, is a discharge of the first necessity. I have never known an instance of a person's being attacked by the yellow fever in whom this discharge was constant, and equally diffused all over the body. Its effects are equally salutary in preventing the plague. So well known is this fact, that Mr. Volney informs us, in his Travels into Egypt, that the common salutation at Cairo, during the prevalence of the plague, is, “Do you sweat freely?” For the purpose of promoting this excretion, flannel shirts or waistcoats worn next to the skin have been found more useful than linen. As the perspiration and sweats, which are thus discharged in a pestilential season, are often unusual in their quantity, and of a morbid quality, clean body-linen or flannel should be put on every day, and where this is not practicable, that which has been worn should be exchanged every morning and evening for that which has been exposed during the previous day and night, in a dry air.
4. Blood-letting. In addition to the authorities of Dr. Haller and Dr. Hodges, mentioned in another place[16], in favour of this remedy, I shall subjoin a few others. Dr. Mitchell, in his Account of the Yellow Fever which prevailed in Virginia, in the year 1741, informs us, that it was often prevented in persons who were under the influence of its remote cause, by the loss of a few ounces of blood. It was formerly a practice among the physicians in St. Domingo, to bleed whole regiments of troops as soon as they arrived from France, by which means they were preserved from the malignant fever of the island.
During the short visit paid to this city, in the year 1798, by Dr. Borland, a respectable physician of the British army, he put into my hands the following communication. “In the beginning of August, 1797, 109 Dutch artillery arrived at Port au Prince, in the Bangalore transport. The florid appearance of the men, their cumbersome clothing, and the season of the year, seemed all unfavourable omens of the melancholy fate we presumed awaited them. It was, however, thought a favourable opportunity, by Dr. Jackson and myself, to try what could be done in warding off the fever. It was accordingly suggested to Monsieur Conturier, the chief surgeon of the foreign troops, and the surgeon of the regiment, that the whole detachment should be blooded freely, and that, the morning after, a dose of physic should be administered to every man. This was implicitly complied with, a day or two after, and at this moment in which I write, although a period of four months has elapsed, but two of that detachment have died, one of whom was in a dangerous state when he landed. A success unparalleled during the war in St Domingo! It is true, several have been attacked with the disease, but in those the symptoms were less violent, and readily subsided by the use of the lancet.