Hereditary Transmission of the Leprosy.
Few facts in the history of tubercular leprosy seem to be more universally admitted by all writers on the disease, both ancient and modern, than the transmission of the predisposition to it from parents to offspring. The Greek and Arabian physicians considered it as a malady in which all the fluids of the body were equally diseased (corrumpens pariter omnes humores corporis). “Fit itaque (adds Haly Abbas, the well-known Arabian author of the tenth century, in his chapter “De Elephantia”), “cum humoribus spermatis corruptio, cum et humores et sperma ex sanguine fiant, in tantum, ut in generatione passio haec transeat in filios.” (Theoric, lib. viii. cap. 15.) Avicenna and the later Arabian authors, with Theodoric, Lanfranc, and other European writers of the middle ages, express a similar belief in the hereditary transmission of the disease; and in the same spirit, our countryman Gilbert, writing, as we have already seen, in the thirteenth century, observes, “Lepra est interdum morbus primus, sicut ex spermatibus primis matris et patris Leprosis. Sanguis enim corruptus interius, qui est nutrimentum foetus, corrumpit foetum.”[277]
Amid the scattered fragments relative to the former history of leprosy in this country, it can scarcely be expected that we should have preserved for us any individual data bearing directly upon the transmission of the disease from father to son. I have met, however, with one notice, which, though imperfect, it may not be considered uninteresting to quote in regard to the present question. In the Burgh Records of Glasgow for 1581, Patrick Bogle is ordered to be inspected for leprosy;[278] and eight years afterwards (1589) “Robert Bogill, sone to Patrick Bogle,” is reported as an inmate of the leper-house belonging to the city.[279]
It is unnecessary to adduce the opinions of modern authors in support of the occasional hereditary transmission of leprosy, as all observers who have described the disease from their own observations, and that in the most different and distant parts of the world, seem uniformly agreed upon this point. Dr. Heineken, in his account of the inmates of the leper hospital at Funchal, Madeira, in 1825,[280] states that in three of the cases no hereditary taint was known; the aunt of a fourth (p. 21) was a lazar; the uncle and two brothers of a fifth (p. 18) laboured under the same disease; the mother, brother, and son of a sixth (p. 19), were lepers, and all of them affected before himself; and in a seventh case (a female aged 35) her father, mother, three sisters, and two brothers, had already all died of elephantiasis.
Among the seven cases of elephantiasis seen by Dr. Kinnis in the Mauritius,[281] three were Mozambique slaves, and could give no satisfactory account of their parentage. Of the remaining four—the first could give no history of her father and mother, but had brothers and sisters in perfect health: the ancestors of the second patient had not been affected with leprosy, but her husband had laboured under it for two years before death: the third case was a daughter of these parents, and one of her brothers had died of elephantiasis: the fourth patient appeared to have inherited the predisposition from the family of his maternal grandmother, who was never attacked herself, but who lost two sisters and three nieces by the disease.
These and other similar data show that the predisposition to leprosy, like the predisposition to other hereditary diseases, may occasionally show itself only in one or two individual members of a family; and may sometimes lie dormant for one or two generations, to reappear in a subsequent one. “God and Nature,” says the reverend author of a description of the Faroe Isles, formerly quoted, “deals wonderfully with such people (lepers) in their marriages, for amongst the children, they beget some clean and some unclean. It has also been taken notice of that two living together in marriage, though the one be found infected, they live together as before, as long as one doth but murmur of it, till the magistrate doth separate them, and yet the sound remaineth uninfected; whereas another is often taken with the disease by a very little conversation.... What is this? but that God confirms the truth of his word, taking pleasure in them that live in a just wedlock, and wander in lawful ways, putting their hopes in him, that neither fire nor water, contagious disease, nor dangerous pestilence shall hurt them.”[282]
In some of the few districts of Europe in which cases of the disease have continued to linger down to a late period, the malady seems to be transmitted through an old hereditary taint in particular families, rather than generated by existing external circumstances acting on the bodies of those who now become its victims. The tubercular leprosy exists still, or at least existed lately, in the districts of Martigues and Vitrolles[283] in the south of France. The cases, though very few, have still been well marked. M. Vidal, who, towards the end of last century, described several instances of the disease which he saw at Martigues, states that, with one problematical exception, the malady was in every case hereditary.[284] “May we not,” he adds, “conclude from this, that if the local causes which are generally assigned for leprosy be true, they have not, at least in our country, sufficient power to originate the disease (la faire naître), but generally only to develope and perpetuate it in the descendants of ancient lepers?”[285] The same family predisposition probably perpetuated the malady for some generations in the few cases that occurred in Shetland, in the latter part of the last century. The case of the Shetlander Berns, as mentioned in a preceding Part, was an instance in which the disease was apparently the result of hereditary transmission from his ancestry.
The predisposition from hereditary constitution to leprosy, and some other diseases, was well known to our forefathers; and, if we place credit in the account of the “auld manneris” of the Scotch antecedently to the reign of Malcolm Canmore, as “compilit be the nobil clerke, Maister Hector Boëce, Channon of Aberdene,” they were accustomed to practise hygienic measures that were assuredly more summary than humane, in order to arrest the diffusion of disease by such channels. For, to quote the words of Boëce:—“He that was trublit with the falling evil (epilepsy), or fallin daft or wod (insane), or having sic infirmitie as succedis be heritage fra the fader to the son, was geldit (castratus), that his infekit blude suld spreid na forthir. The women that was fallin Lipper, or had any other infection of blude, was banist fra the cumpany of men, and gif scho consavit barne under sic infirmitie, baith scho and hir barne war buryit quik (if she conceived a child under such infirmity, both she and her child were buried alive”).[286]
External exciting causes of Leprosy in the Middle Ages.