Venesection was succeeded by large doses of calomel, and the calomel era continued on almost to our own generation.

As a rule, however, the medieval physicians trusted nature much more than did their colleagues of modern history—that is, after the Renaissance until the present epoch of medical science began. It has always been difficult, however, for physicians to continue long in the persuasion that nature is a helpful auxiliary, and not a hampering factor to be combated. It is all the more to the credit of the medieval physicians to find, then, that in spite of many absurdities they continued for all the later centuries of the Middle Ages to extol the value of the natural means of cure.

I shall have much to say of John of Ardern in the chapter on Medieval Surgeons of the West of Europe, but he deserves a place also in the chapter on Medicine. Ardern's advice to patients suffering from renal disease, which is contained in a separate tract of his lesser writings with the title in an old English version of " The Governaunce of Nefretykes," is extremely interesting, because it shows very clearly how long ago thoughtful physicians anticipated most of the directions that we now give such patients. Though we are inclined to think that any real knowledge of renal disease is quite modern, and above all has come since Bright's time, this paragraph of Ardern's shows how long before definite pathological knowledge had developed, careful clinical observation worked out empirically the indications of the affection. The paragraph is of special interest, because it contains the first reference to the possible danger that there may be for sufferers from kidney disease using the dark or red meats rather than the white meats. The tradition as to the distinction between the red and white meats has continued ever since his time, and though our modern chemistry does not enable us to find any such distinction between these substances as would justify the differentiation thus dwelt on, it has been maintained for no other reason that I have ever been able to find than because of the long years of tradition and clinical observation behind it.*

'4 Nefretykes must putte awey ire, hyghly and moche besynesse and almanere [business and all manner of] thynge that longeth to the soule saff [save] only joye. . . . They schulle forbere almanere metys that ben to grete of substaunse and viscous, as olde beeff that is myghtyly pooudryd and enharded with salt and also fressch porke but yf it lye in salt iiii dayes afore. . . . They mowe use grete wyne and the fflessch of calvys that ben soowkynge and also of all ffowlys saff thoo that ben of the lakys and dichys [dykes?] . . . and squamous fTyssches, i.e., fyssch of the rivere, of the stony waterys and rennynge ryveres and not of the standyne waterys and they schulle eschywe [eschew] almaner mete made of paast [pastries] and all bred that is dowgh bakene and all fatnesse. And they schulle use the reynes of te beeste other roste or sode. And in especiall he schall use a ffowl that is callyd Cauda tremula or Wagstertte [the wagtail, an English bird] other fressch or salte or bakene withoute drynesse ffor and it be drye it is nought woorth. And note that the use of the powdir or of the flessch of the Wagstertte avayleth gretly to breke the stone in the bladdere."*

* Some of these old medical traditions come down to us from many more centuries than we have any idea of until we begin to trace them. Ordinarily it is presumed that the advice with regard to the taking of small amounts of fluid during meals comes to us from the modern physiologists. In "The Babees Book," a volume on etiquette for young folks issued in the thirteenth century, there is among other advices, as, for instance, " not to laugh or speak while the mouth is full of meat or drink," and also " not to pick the teeth with knife or straw or wand or stick at table," this warning: " While thou holdest meat in mouth beware to drink ; that is an unhonest chare; and also physick forbids it quite." It was " an unhonest chare " because the drinking-cups were used in common, and drinking with meat in the mouth led to their soiling, to the disgust of succeeding drinkers. All the generations ever since have been in slavery to the expression that " physic forbids it quite," and now we know without good reason.

* The book called " The Hundred Merry Jests " suggests that the wagtail is light of digestion because it is ever on the wing, and^therefore had, as it were, an essential lightness.