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.