largely against that particular combination of factors needed to make leprosy. It was a _morbus miseriae_ of the Middle Ages, but on the whole not a very common one; and it was easily shaken off by the national life when the conditions changed ever so little. It was all the more easily shaken off by reason of the facilities for divorce, the prohibition of marriage, and the monastic discipline. The staple diet as a cause of leprosy was suspected in the Middle Ages, and by writers as ancient as Galen. It is not without significance that the minute directions for the dieting of the lepers in the rich hospital of Sherburn, near Durham, urge special caution as to the freshness of the fish: when fresh fish was not to be had, red herrings might be substituted, but only if they were well cured, not putrid nor corrupt. Those directions were in accordance with the best medical teaching of the time on the dietetics of leprosy, or on how to prevent leprosy, as it is given with considerable minuteness in Gordonio and Gilbert[209]. On the other hand we find a singular ordinance of the Scots Parliament at Scone in 1386, or some forty years after the date of the Durham regulations: “Gif ony man brings to the market corrupt swine or salmond to be sauld, they sall be taken by the Bailie and incontinent without ony question sall be sent to the lepper-folke; and gif there be na lepper-folke, they sall be destroyed alluterlie[210].” Nothing could be more significant for the prevalence and persistence of leprosy in Scotland[211]. Putrid fish and pork did actually come to market; the dangers of them as regarded the production of leprosy were unsuspected; and the lepers (genuine or mistaken) were actually directed to be fed with them. Such food for “lepers” could only have fed the disease; and if it be the case that genuine leprosy was met with in Edinburgh and Glasgow more than two centuries after it ceased to be heard of in England, we need be at no loss to assign the reason why the disease was more inveterate in the one country than in the other. CHAPTER III. THE BLACK DEATH.