The Canon of Medicine

...they are not cooled like others, nor do they tolerate those medicines which, besides cooling, also moisten; but they admit only those from among the cooling ones which can simultaneously dry. Here, Galen, just as Avicenna, in the cure of formica corrosiva corrosive ant, a type of eating ulcer, likewise prohibits moistening in the treatment of herpes comedens eating herpes, which he nevertheless approves of in cases of erysipelas. And therefore, the same Galen adds: "One must not apply lettuce, or knotgrass, or lentils from ponds, or marshy lotus, or anthyllis a medicinal herb, or psyllium, or purslane, or endive, or houseleek, or anything similar which could moisten, to those conditions which are suitable for erysipelas." But here a not insignificant scruple remains, because Avicenna approves of these very herbs, or a large part of them, at the beginning of corrosive formica, writing thus: "And administering [remedies] at the beginning of it, namely corrosive formica, such as lettuce and water-lily, and houseleek, and purslane..." so that Avicenna appears to contradict himself clearly. For if, as he himself had said a little above, the moistening which is due for erysipelas must be avoided in the curing of corrosive formica, why does Avicenna, immediately afterwards, command or order the administration of lettuce, houseleek, and purslane—which Galen, in Book XIV of the Art of Healing, praises for the cure of erysipelas, but in the second book to Glaucon a student of Galen judges to be avoided in herpes because of their excessive humidity? Gentilis, who seemed to have noticed this contradiction in Avicenna's words, says not alone [should they be used] but mixed with other drying agents: for example, lentils, which are cold and moist, with houseleek, which is cold and dry. And the same Gentilis says this not about corrosive formica, but about the ambulant type, in which, as in any other species of formica according to him, there is some ulceration, and therefore the humidity which must be dried out causes the doubt. Wherefore, I do not believe that Gentilis thought he was the intellect of Avicenna whom he strives to excuse; it may suffice now to have proven that Avicenna accepted erysipelas for formica, and formica for erysipelas, not without great confusion: since he adapted the remedies that were for erysipelas (namely cooling and moistening) to corrosive formica, and those things which were suitable for formica—whether corrosive or miliaris millet-seed-like, a type of rash—namely, very drying things, he transferred these to erysipelas. I have mentioned so many things we said about Avicenna confounding the diseases of the young, so that I might show that he used a more liberal confusion in pruna a type of carbuncle and ignis persicus Persian fire; and lest perhaps one suspects that in such long digressions we have sought out things that pertain nothing to our purpose. Yet it was necessary for us to show beforehand that it was not consistent for Avicenna what ignis persicus was. For sometimes he says it is generated from thick and melancholic black bile blood, as we also admonished before. Now, the same man makes ignis persicus the same genus as pruna, when he says: "These two names are perhaps absolute [terms] over all corrosive, blistering pustules that cause an eschar a slough or scab to occur, such as a burn or cautery makes occur." Now, however, he differentiates, as when he says pruna is more melancholic, while ignis persicus is more choleric. Sometimes he draws it to formica comedens eating ant, as when he writes thus, and sometimes the name ignis persicus is applied absolutely to those [conditions] upon which there is a pustule of the genus of formica comedens that burns and dries. Sometimes he transfers it to formica miliaris, as when he writes in this manner: "And sometimes there are, with the species of formica, miliaris fevers of vehement and pernicious heat." As if, in Avicenna’s view, ignis persicus and formica miliaris do not differ, and it does not matter much whether one manifests the signs of ignis persicus or formica miliaris. And indeed, to one looking more diligently, formica miliaris and ignis persicus differ little or not at all according to Avicenna; for in both there are blisters similar to millet, as Rasis Rhazes, Paulus Paul of Aegina, and Galen in Book XIII of the Art of Healing agree. Wherefore, if we follow Avicenna, not only the form but also the matter is found to be the same in both diseases, since both ignis persicus and formica miliaris, according to Avicenna, are made from cholera bile mixed with melancholia.

Concerning elephantiasis and leprosy. Doubt the Thirteenth.

A decorative initial 'I' features floral or vegetal motifs.
It must be noted that one genus of disease is signified by the word elephantiasis in the books of the Arabs, and another in the books of the Greeks. Avicenna and Rasis, indeed, accept elephantiasis for a disease in which the feet and legs swell beyond measure. Paulus, Galen, and all the Greek authors understand by the same word the disease which Avicenna and the younger physicians call lepra leprosy. Therefore, to approach the matter more closely: that elephantiasis among the Greeks is what is called lepra among the Arabs and the younger physicians, is demonstrated thus. According to Paulus, elephantiasis is a cancer occupying the whole body, whence the same Paulus Aegineta says: "If a cancer infecting only one limb is, nevertheless, according to the opinion of Hippocrates, incurable, how much more will the elephant—which is a certain universal cancer—surpass all curing?" Avicenna writes the same opinion in his fourth book in these words: "And since cancer, which is the leprosy of a member, is among those for which there is no cure, what shall we say of the leprosy which is the cancer of the whole body?" Avicenna had said the same thing near the beginnings of that chapter in which he deals with lepra, that it is like a cancer common to the whole body. But Paulus also judges that elephantiasis is generated from the vice of the same humors as Avicenna’s lepra; and just as Paulus posited a less evil species of elephantiasis which takes its origin from a certain dregs of blood, and another which is made worse by yellow bile, so also Avicenna decides concerning the two species of lepra, of which one is likewise generated from the dregs of blood, the other from yellow bile converted by "roasting" referring to the internal heat of the body altering the humors. And Paulus does not use a different cure for elephantiasis than Avicenna uses for lepra. Nor does Galen, writing about elephantiasis in the second book of the Art of Healing to Glaucon, differ from Paulus, for he accords with Avicenna who writes about lepra. Indeed, all those words of Avicenna—that lepra multiplies because of the heat of the air and the malice of food, its essence being from the genus of fish and salted meat, and gross meat, and the flesh of donkeys, and lentils—all these words of Avicenna, however barbarously they may be written, are nevertheless taken from Galen in the chapter on elephantiasis. What, indeed, if Galen had not understood by elephantiasis the disease we have mentioned? That absurdity would follow: that Galen, easily the prince of physicians, who wrote so many volumes on medicine so carefully and so copiously, made no mention in his books of that disease which surpasses all the rest in magnitude, which we commonly call lepra. By Galen's books, however, I understand those which the same author left written in his own language. For in those which we have translated either from the Greek or the Arabic language, there is very much ambiguity in this word lepra. For sometimes the translator, where he found elephantiasis written in the Greek Galenic codex, interpreted it as lepra; where he found lepra, he changed nothing, but used the same word, although among the Greek authors, lepra is one disease, and elephantiasis is another. For lepra (as Galen says in his book on tumors against nature) is a passion of the skin alone, which cannot be said of elephantiasis. Since in that disease which is named elephantiasis by the Greeks, not only the skin but also the flesh and the bones—as Cornelius Celsus also testifies—are usually corrupted. The name elephantiasis is drawn from the likeness to an elephant, because (as Galen says in the sixth book on the causes of accidents) those who suffer from this disease have black flesh and skin full of tubercles, just like the skin of elephants. Some think elephantiasis is so called because of the magnitude of the disease, which yields to almost no remedy. Some [think it is so named] because, just as an elephant lives the longest of all animals, so this disease is the longest lasting. Indeed, all these properties suit no other disease more than that which we commonly call lepra. Avicenna treats of elephantiasis in the third book, but he deals with lepra in the fourth, with such an interval that he seems to have thought elephantiasis a genus entirely distinct from lepra, especially since the same Avicenna placed elephantiasis not among the diseases of figure, as Galen did, but in the first book, [as a disease] of quantity.