12. We believe, that this contagion does not take place but by long frequenting the company of the infected, or by carnal knowlege. Besides, we have observed, that even such long frequenting, or cohabiting with them, are not always sufficient to communicate the disease; because we have seen women cohabit with their husbands, and husbands with their wives, in the distemper, while one is sound, and the other infected. We see families communicate and live with leprous persons, and yet never be infected; and thus, altho’ experience, and the information of the sick, prove the contagion, we are of opinion, that there must be a particular disposition in people to receive the poison of the leprosy.
13. As to what regards the distemper’s being hereditary, it is assuredly so. We have seen intire families infected; and almost every child of a leprous father or mother fall insensibly into the leprosy; and yet, in several other families, we have seen some children sound, and others tainted; the father has died of the disease, and the children grew old without any infection: so that, tho’ it is certainly hereditary, yet we believe it is of the same nature with those in families troubled with the consumption, gravel, and other hereditary distempers; which are transmitted from father to son, without being so very regular, as to affect every one of the family.
14. We could never find out any certain rule of judging, at what age the disease shews itself first in those, who were begotten by infected parents: but we have, as far as we could, observed, with regard to women or girls, that the symptoms begin with the menses, and continue slightly till they have lain in of one or two children: but that then more visible, and indeed more cruel, symptoms appeared. As to men, or infants, there is no rule to know it in them.
15. For the explanation of the causes, symptoms, and what we think the most likely means of cure, we refer to a particular dissertation. Let it suffice here to observe, that we do not imagine, that the air, water, or manner of living, can produce it; for we have found as many sick in the low marshy places, as in more airy saline places: and if many Negroes were infected in the Grand Terre, where they drink the foul waters of ponds and lakes, we see an equal number ill in places, where they have fresh rivers and running waters; but they may prove proper causes for unlocking, and disposing persons to receive, the disease.