from John Hippisley (1764) On the Populousness of Africa. Reprinted in Population and Development Review (1998)24:601-608.

Neither are the fruits of promiscuous lewdness so bitter in that part of the world as they are in Europe, and consequently not so hurtful to procreation. The Lues Venerea and the Gonorrhoea are indeed both known in those countries of Africa we are acquainted with; but their symptoms are very mild, the infection not so communicable as in our parts of the world, and the cure vastly more easy. The natives think nothing of them, nor are they, however carelesly managed, scarcely ever attended with rotten bones, or an impaired habit of body. The only medicine among these people for the Gonorrhoea, and which always carries it off, is an infusion of diuretick and vulnerary herbs; and the care of the confirmed Tabes, if it deserves that name, is effected by a strict and warm confinement in the house, a rigid abstinence from all high-seasoned animal food and taking the decoction of sarsaparilla. The sarsa, I suppose, was originally introduced among them by some European, as it does not grow in Africa: its good effects must however have been very manifest for them to have adopted the practice so universally among themselves, that sarsa is become an article in trade, is constantly brought to the Gold Coast, sold to the traders there, and carried to the inland parts of the country.[fn]

[fn] We might account for the mildness of the symptoms in this disorder from the excessive perspiration, did not the same take place also in the West Indies, where the symptoms of Lues Venerea are however, by what I have heard, not quite so severe as in Europe. The true reason undoubtedly is, its not being a malady peculiar to the climate; for it has been observed by physicians, that exotic disorders as well as plants degenerate, and will in time die away. The Elephantiasis of the Greeks, and the Leprosy of the Egyptians, continued but a time in the western parts of Europe, and are now hardly ever seen. The Venereal disease has also declined in its violence of symptoms in Europe, insomuch that Dr. Astruc ventures to prognosticate that in a course of years it will be totally extirpated. This way of reasoning may appear singular enough in the subject before us, it being generally agreed to now, that the Venereal disease in Europe was occasioned by Columbus's sailors bringing the Yaws from America, a cuticular disorder in that country, but which changed its appearance from the alteration of climate. Now the Yaws is as peculiar to Africa as it ever was to the West Indies: how then shall the Venereal disease, which owes its origin to an endemic of Africa, be called a foreign one? We answer, By its entire variation of symptoms; a circumstance altogether sufficient to make us reckon it a new disease. A negro family carried from Guinea to Europe would find their constitutions quickly altered; and if their descendants, after the second or third generation, were removed to Guinea, they would feel every effect of that climate in the same manner, and be subject to the same disorders, as the ab origine Europeans. The Burgundy vine transplanted to the Cape of Good Hope produced the fine Constantia wine, as different from Burgundy as one wine can be from another. Should the Cape vine be now transplanted to France, the grape of it would doubtless produce a wine different both from the Burgundy or Constantia.