Having little experience of my own with regard to diseases at sea in cold climates, I cannot recommend any particular precautions; but Dr. Lind thinks that garlick infused in spirits is one of the best preservatives against the bad effects of cold and wet. The French ships of war are furnished with great quantities of garlick as an article of victualling, and its effects seem to be very salutary. It would appear, that substances of this kind are very conducive to health in hot climates also. I was informed by Capt. Caldwell, that, when he commanded a sloop of war on the coast of Guinea, he was supplied with a large quantity of shalots by a Portuguese about the time he left the coast, and his men were remarkably healthy on the passage to the West Indies, while the other ships in company, who wanted this supply, were very sickly.
But besides the obvious and sensible qualities of the air above mentioned, there are certain obscure properties which we do not understand, and which we find difficult to investigate; for there are diseases prevailing in certain places which seem to depend on some latent state of the air. Of this kind is the complaint of the liver, so common in the East Indies, yet almost entirely unknown in the West Indies; and in the West Indies there are certain diseases which prevail in one island and not in another; such as the elephantiasis[41] of Barbadoes, which is an affection of the lymphatics peculiar to that island. In the climates of Europe there are also certain obscure conditions of the air that favour one epidemic more than another, and in some years more than others[42]. All this is very mysterious to us; and although we could detect these properties of the air, we probably could not prevent their bad effects, since man must every where breathe the air, whatever its qualities may be.
SECT. II.
Of Foul Air from the Neglect of Cleanliness in Men’s Persons—Infection.
Nature has wisely so contrived our senses and instincts, that the neglect of cleanliness renders a person loathsome and offensive to himself and others, thereby guarding against those fatal diseases that arise from bodily filth. The noxious air we speak of is generated by men keeping the same clothes too long in contact with the body, while they are at the same time confined and crowded in small and ill-ventilated apartments. Such is the origin of the jail fever, otherwise called the ship and hospital fever; and it seems to be with reason that Dr. Cullen ascribes the low, nervous fever of Britain to a similar origin, being caused, as he thinks, by an infection of a milder kind, arising in the clothes and houses of the poor, who, from slovenliness or indigence, neglect to change their linen, and air their houses.
Man is evidently more subject to disease than any other species of the animal creation, owing partly to the natural feebleness of his frame, but still more perhaps to the artificial modes of life which his reason leads him to adopt. There is no circumstance of this kind by which health is more affected than by clothing. Some of the most fatal and pestilential diseases are produced and communicated by it; for we see that the greater number of fevers, particularly those of the low and malignant sort, may be traced to the want of personal cleanliness.
There are few subjects more mysterious and difficult of investigation than this of infection. The origin of specific contagions, such as the small pox and the venereal disease, seems to be almost beyond the reach of a conjecture; and why all the contagions we know, excepting that of the bite of a mad dog, should be confined to one species of animal, their effects not being communicable to any other, is equally unaccountable. Why is the body incapable of being affected more than once by certain morbid poisons; and whence comes the striking and curious differences of susceptibility to infection in different individuals at the same time, and of the same individual at different times?
It would appear that the infection of fever, which we are chiefly to consider here, does not, like some of the diseases above mentioned, depend on the continued propagation of a certain poison, but that it may spontaneously arise from a concurrence of circumstances, producing a long stagnation of the effluvia of the body on the clothes, for want of clean linen, while people are excluded from the free air, as in jails, hospitals, or ships.
In order, therefore, to preserve the crews of ships from such diseases, means should be taken not only to prevent the introduction of infection already existing, but to prevent the generation of it on board.
1. Means of preventing the Introduction of Infection.
War being a state of violence and confusion, in which the hurry and emergency of service may be such as to render it impossible to put in practice all the rules which might be laid down concerning the preservation of health, yet it is necessary that those who direct the navy, either in a civil or military capacity, should be aware of the causes of sickness and mortality, in order to guard against them as far as is practicable. From an indolent acquiescence in this idea of the hardships and inconveniences of war being unavoidable, I have known neglect to arise in the conduct of officers with regard to those under their command, as if it was not the duty of a commander to employ his utmost attention to alleviate the misfortunes and mitigate the sufferings of his fellow creatures; and we have seen that much more of the calamities of war arise from disease than from the sword. The like excuse might be framed for the neglect of stores and arms, which, the hurry of service might equally expose to injury. We see, indeed, infinite pains taken to prevent cordage from rotting, and arms from rusting; but however precious these may be as the necessary resources of war, it will not be disputed that the lives of men are still more so; yet, though there is the additional inducement of humanity to watch over the health of men, I do not think that this, in general, is studied with a degree of attention equal to what is bestowed on some inanimate objects.