Observations on the Diseases of Seamen. Blane Gilbert
more used to the bad air, the sickness ceased in the course of a few weeks.
In the accounts given in the tables, the French prizes are not included, for the disorderly state in which they were at this time prevented my receiving regular returns: but having made inquiry concerning the mortality in the Ville de Paris, I found, that of a crew of three hundred and twelve men, there died ten in the month of May, and there were thirty sent to the hospital, whose cases were so unfavourable, that about one half died. The only diseases were fevers. The surgeon of the Ardent told me about the same time, that one third of the crew of that ship was ill of fevers.
The second cause of the prevalence of sickness, while the fleet was at Jamaica, was, the watering duty, which was carried on at Rock-fort, about three leagues from Port Royal. It was the practice of many of the ships to leave the water casks on shore all night, with men to watch them; and as there is a land wind in the night, which blows over some ponds and marshes, there were hardly any of the men employed on that duty who were not seized with a fever of a very bad sort, of which a great many died. The ships that followed a different practice were somewhat longer in watering; but this was much more than compensated by their preserving the health and saving the lives of their men.
The land wind which blows on the shore in the night time, is a circumstance in which Jamaica differs from the small islands to windward, over which the trade wind blows without any interruption: but though this land wind blows upon Port Royal from some marshes at a few miles distance, it does not seem to produce sickness, for it is a very healthy place, and several of the ships enjoyed as good health as in the best situations on the windward station. The bay which forms this harbour is bounded towards the sea by a peninsula of a singular form, being more than ten miles in length, and not a quarter of a mile broad at any part. Great part of it is swampy and overgrown with mangroves, and though of such small extent, we fancied that some of the ships that lay immediately to leeward of this part were more sickly than those that were close to the town of Port Royal, which stands at the very extremity of this long peninsula upon a dry, gravelly soil.
The weather this month was uniformly dry in port; but at sea the air was moist and hazy. Between Jamaica and Hispaniola, where part of the squadron was left to cruise, dead calms prevailed; and this, joined to the moisture of the air, was probably what caused the flux to prevail chiefly in this part of the fleet. At Port Royal, on the contrary, there was a strong dry breeze, which set in every day about nine o’clock in the morning, and blew all day so fresh, that there was frequently danger in passing from one ship to another in boats. This is called, in the language of the country, the fiery sea breeze, an epithet which it seems to have got not from its absolute heat, but from the feverish feeling which it occasions by drying up the perspiration. It was remarked, that this breeze was stronger this season than had ever been remembered; and it sometimes even blew all night, preventing the land breeze from taking its usual course. This year was farther remarkable for the want of the rains that were wont to fall in the months of May and June. We shall have occasion to remark hereafter, that this was a very uncommon season also in Europe and America. The heat, by the thermometer, this month, on board of a ship at Port Royal, was, in general, when lowest in the night, at 77°, and when highest in the day, in the shade, at 83°.
There was a considerable increase of scurvy in this month, compared with the former months of this campaign; but very inconsiderable, compared with what had occurred in cruises of the same length in former years. The last division of the fleet had been at sea seven weeks, all but one day, when it arrived at Port Royal; and though the scurvy had appeared in several of the ships, it did not prevail in any of them to a great degree, except in the Nonsuch. Out of fourteen deaths which happened in the whole fleet from this disease, in May, seven of them were in this ship, and several were sent from her to the hospital in the last and most desperate stage of it. But, upon the whole, the cases of the true sea scurvy in the fleet, in general, were few and slight, and a great many of those given in the reports under the head of scurvy, were cutaneous eruptions or ulcers, not properly to be classed with it.
The cruise in the preceding year to windward of Martinico, may be compared with that in May of this year; for the fleet in both cases had been at sea about the same length of time. But the comparison is very greatly in favour of the latter, which is most probably to be imputed to the plentiful supply of melasses, wine, sour krout, and essence of malt. But no adequate reason that I could discover can be assigned for the prevalence of it in the Nonsuch to a degree so much more violent than in the other ships; and it was here farther remarkable, that it attacked every description of men indiscriminately; for I was assured by the officers and by the surgeon, that not only the helpless and dispirited landsman was affected, but old seamen, who had never before suffered from it on the longest cruises. I have been led by this, and some other facts, to suspect that there may be something contagious in this disease.
The greater part of the fleet remained at Jamaica during this month, refitting and watering. Twelve ships of the line were sent to sea on the 17th, under the command of Rear-admiral Drake, but not being able to get to windward on account of the fresh breezes that prevailed, they returned to Port Royal on the 28th. Such of these ships as were sickly, became more healthy while at sea; but some bad fevers arose, particularly in the Princessa; and it is a curious circumstance, that these fevers attacked only those men who had been on shore on the watering duty; from which it would appear, that something caught or imbibed, which is the cause of the fever, lies inactive for some time in the constitution, some of the men not having been affected for more than a week after they had been at sea.
The weather continued dry and windy, as in the former month; but the heat was in general about two degrees higher, the thermometer varying from 79° to 84½°.
Transcriber’s Keys:
A Proportion of those taken ill in the Course of this Month.
B Proportion of those who died, in relation to the Numbers of the Sick.
The proportion of deaths in relation to the whole numbers on board, was one in one hundred and thirty-eight.
There was only one in thirty of the sick sent to the hospital in the course of this month.
There was an increase both in the numbers and fatality of fevers. This increase was chiefly in that sort of fever which depends on the air and climate, the greater part of which was caught on the watering duty. There was a diminution of those fevers depending on infection, and the foul air of ships, which arose in the French prizes. The care that was taken in purifying these ships was very effectual; for only four died this month in the Ville de Paris, and fewer also were sent to the hospital than in May. The increase of the other kind of fever was chiefly owing to there being a greater number of ships in port, the crews of which were employed in watering, and partly, no doubt, to the increase of heat in the weather. The ships in which the fevers were most fatal were the Monarch, the Duke, the Torbay, and the Resolution. The sickness in the Duke was still in a great measure owing to the same infection that had hitherto prevailed; for this ship had never been cleared of the infectious fever, for want of room at the hospital. That which broke out in the Torbay was also of the low infectious kind, few of them having the symptoms of that which is peculiar to the climate, which prevailed in the other ships. This ship, though formerly very subject to infectious complaints, had been remarkably healthy for some time past; but it would appear that there was a large stock of latent infection, which shewed itself from time to time.
Some ships, particularly the Montague and Royal Oak, had no increase of fevers or other complaints, though the one lay in port for seven, and the other for eleven weeks, and were more or less exposed to the causes of sickness which affected the rest of the fleet. This is a proof, among many others, that a particular combination of causes is necessary to produce a disease: no single one, however powerful, being sufficient, without the concurrence of others. What seemed to be wanting here was the predisposition requisite for the admission of disease into the constitution; for the ships that enjoyed this happy exemption were such as had long-established and well-regulated crews, accustomed to the service and climate.
There had been this month a diminution both of the numbers and mortality of fluxes, which is agreeable