It hath been alleged, that the scurvy is much owing to the coldness of the air, which checks perspiration, and on that account is the endemic distemper of the northern nations, particularly of those around the Baltic*. The fact is partly true, but I doubt not so the cause. In those regions, by the long and severe winters, the cattle destitute of pasture can barely live, and are therefore unfit for use; so that the people, for their provision during that season, are obliged to slaughter them by the end of autumn, and to salt them for above half the year. This putrid diet then, on which they must subsist so long, and to which the inhabitants of the south are not reduced, seems to be the chief cause of the disease. And if we reflect that the lower people of the north have few or no greens nor fruit in the winter, scarce any fermented liquors, and often live in damp, foul, and ill-aired houses, it is easy to conceive how they should become liable to the same distemper with seamen; whilst others of as high a latitude, but who live in a different manner, keep free from it. Thus we are informed by Linnaeus, that the Laplanders, one of the most hyperborean nations, know nothing of the scurvy*; for which no other reason can be assigned than their never eating salted meats, nor indeed salt with any thing, but their using all the winter the fresh flesh of their rain-deer.
[* Bartholin. Med. Danor. Domestic p. 98.]
[** Linnaei Flora Lapponica, p. 8, 9.]
This exemption of the Laplanders from the general distemper of the north is the more observable, as they seldom taste vegetables, bread never, as we farther learn from that celebrated author. Yet in the very provinces which border on Lapland, where they use bread, but scarcely any other vegetable, and eat salted meats, they are as much troubled with the scurvy as in any other country*. But let us incidentally remark, that the late improvements in agriculture, gardening, and the other arts of life, by extending their influence to the remotest parts of Europe, and to the lowest people, begin sensibly to lessen the frequency of that complaint, even in those climates that have been once the most afflicted with it.
[* Linnaeus in several parts of his work confirms what is here said of salted meats, as one of the chief causes of the scurvy. See Amoenitat. Acad. vol. v. p. 6. et seq. p. 42.]
It hath also been asserted, that men living on shore will be affected with the scurvy, though they have never been confined to salted meats; but of this I have never known any instance, except in those who breathed a marshy air, or what was otherwise putrid, and who wanted exercise, fruits, and green vegetables: under such circumstances it must be granted, that the humours will corrupt in the same manner, though not in the same degree, with those of mariners. Thus, in the late war, when Sisinghurst Castle in Kent was filled with French prisoners, the scurvy broke out among them, notwithstanding they had never been served with salted victuals in England; but had daily had an allowance of fresh meat, and of bread in proportion, though without greens or any other vegetable. The surgeon who attended them, and from whom I received this information, having formerly been employed in the navy, was the better able to judge of the disorder and to cure it. Besides the deficiency of herbs, he observed that the wards were foul and crowded, the house damp (from a moat that surrounded it) and that the bounds allotted for taking the air were so small, and in wet weather so sloughy, that the men seldom went out. He added, that a representation having been made, he had been empowered to furnish the prisoners with roots and greens for boiling in their soup, and to quarter the sick in a neighbouring village in a dry situation, with liberty to go out for air and exercise; and that by these means they had all quickly recovered. It is probable, that the scurvy sooner appeared among these strangers, from their having been taken at sea, and consequently more disposed to the disease. My informer further acquainted me, that in the lower and wetter parts of that county, where some of his practice lay, he had now and then met with slighter cases of the scurvy among the common people; such, he said, as lived the whole winter on salted bacon, without fermented liquors, greens, or fruit, a few apples excepted; but, he remarked, that in the winters following a plentiful growth of apples, those peasants were visibly less liable to the disorder.
I have dwelt the longer on this part of my subject, as I look upon the knowledge of the nature and cause of the scurvy to be an essential step towards improving the means of prevention and cure. And I am persuaded, after mature reflection, and the opportunities I have had of conversing with those who, to much sagacity, had joined no small experience in nautical practice, that upon an examination of the several articles, which have either been of old approven, or have of late been introduced into the navy, it will be evident, that though these means may vary in form, and in their mode of operating; yet they all some way contribute towards preventing or correcting putrefaction, whether of the air in the closer parts of a ship, of the meats, of the water, of the clothes and bedding, or of the body itself. And if in this inquiry (which may be made by the way, whilst we take a review of the principal articles of provision, and other methods used by Captain Cook to guard against the scurvy) I say, if in this inquiry it shall appear, that the notion of a septic or putrid origin, is not without foundation, it will be no small encouragement to proceed on that principle, in order further to improve this important branch of medicine.
Captain Cook begins his list of stores with malt. Of this, he says, was made Sweet Wort, and given not only to those men who had manifest symptoms of the scurvy, but to such also as were judged to be most liable to it. Dr. Macbride, who first suggested this preparation, was led (as he says) to the discovery by some experiments that had been laid before this Society; by which it appeared that the air produced by alimentary fermentation was endowed with a power of correcting putrefaction*. The fact he confirmed by numerous trials, and finding this fluid to be fixed air, he justly concluded, that whatever substance proper for food abounded with it, and which could be conveniently carried to sea, would make one of the best provisions against the scurvy; which he then considered as a putrid disease, and as such to be prevented or cured by that powerful kind of antiseptic**. Beer, for instance, had always been esteemed one of the best antiscorbutics; but as that derived all its fixed air from the malt of which it is made, he inferred that malt itself was preferable in long voyages, as it took up less room than the brewed liquor, and would keep longer found. Experience hath since verified this ingenious theory, and the malt hath now gained so much credit in the navy, that there only wanted so long, so healthful, and so celebrated a voyage as this, to rank it among the most indispensable articles of provision. For though Captain Cook remarks, that A proper attention to other things must be joined, and that he is not altogether of opinion, that the wort will be able to cure the scurvy in an advanced state at sea; yet he is persuaded that it is sufficient to prevent that distemper from making any great progress, for a considerable time; and therefore he doth not hesitate to pronounce it _one of the best antiscorbutic medicines yet found out***.
[* Append. to my Observations on the Diseases of the Army.]
[** Macbride's Exper. Eff. passim.]