The duties of wooding and watering are so unwholesome, that negroes, if possible, should be hired to perform them. In general, however, the employing of seamen in filling water and cutting wood is unavoidable, but it should be so managed as not to allow them, on any account, to stay on shore all night; for, besides that the air is then more unwholesome, men, when asleep, are more susceptible of any harm, either from the cold or the impurity of air, than when awake and employed. As the service necessarily requires that men should be on shore more or less, however unwholesome the air may be, means are to be used to prevent its pernicious impressions on the body. Certain internal medicines, such as bitters, aromatics, and small quantities of spirituous liquors, tend to preserve the body from its bad effects. Of the bitters, Peruvian bark is, perhaps, the best; and there is a well-affected instance of its efficacy in the account given by Mr. Robertson of a voyage in the Rainbow to the coast of Africa; and by the same means Count Bonneval and his suite escaped sickness in the camps in Hungary, while half of the army were cut off by fevers. In consequence of Mr. Robertson’s representation of the effects of bark in curing and preventing the fevers of that climate, the ships of war fitted out for the coast of Guinea have been supplied with it gratuitously, and Government would find its account in extending this bounty to all the tropical stations. We have seen, in the former part of this work, that the fever produced by the impure air of marshes may not appear for many days after the noxious principle, whatever it is, has been imbibed; men having been sometimes seized with it more than a week after they had been at sea. It naturally occurs, therefore, that something may be done in the intermediate time to prevent the effects of this bad air; and nothing is more adviseable than to take some doses of Peruvian bark, after clearing the bowels by a purgative. Some facts, related in the first part of this work, show that an interval of ten days or a fortnight may elapse between the imbibing of the poison and its taking effect. And, in order to guard against the diseases of this climate in general, it would be more proper to take some large doses of bark once in either of these periods, than to make a constant practice of taking a little, as I have known some people do, by which they may also render their body in some measure insensible to its good effects. I knew a physician of some eminence in the West Indies, who always enjoyed uninterrupted health, and he imputed it to his taking from half an ounce to an ounce of bark every change and full of the moon, as he thought that fevers of the intermitting and remitting kind, were more apt to occur at these periods. Whether this idea be well founded or not, the practice is proper, upon the other principle that has been mentioned, and the phases of the moon will at least serve as an aid to the memory.