Excerpted from Liber de elephantia 1-3

It behooves the doctor to investigate the putrefaction of stomach fluids which originate from the four humors when its substance comes out singly or in multiple parts. Moreover the putrefaction is caused either from the corruption of the sperm of a male or the seed of a female, or from the corruption of the air or of foods and drink. For from these corrupted humors a disease is born which is accustomed to be named leprosy; investigation of this disease is difficult and laborious in its beginning. Moreover, after it goes out into the open this sickness is difficult to cure. Therefore when we said that this is produced from the four humors, let us begin from the corruption of blood, which seems to be somehow nobler. Therefore if leprosy is caused from corruption of the blood, it is indicated by redness and a hot ulcer and the blood is broken down into putrefaction.

original latin

Si autem ex colore rubeae est corruptione, siccitas et asperitas, macies quoque succedit et hae maxime denotantur in pectore; pustulae etiam in corpore, fissure in manibus sive pedibus, cutis colore citrinus. Si vero ex colere nigre putredine, similiter succedit siccitas, et manuum et pedum fissura et venarum extensio, spasmus quoque et digitorum contractio et totius corporis titillatio, cutis etiam nigredo.

Si vero colera rubea cum colera nigra commixta fuerit, asperitas hoc denotat pectoris et siccitas vocis, fissura quoque pedum et spasmus digitorum. Si calor colore rubeae frigiditatem excellit colore nigre, incenditum maius erit et membra citius fissuram patiuntur et membrorum concatenatio dissolvitur.

Morbus ergo nascens ex sanguine alopicia vocatur. Qui vero ex colera rubea procreatur leonina nuncupatur, ex colera nigra elephantia apellatur, de flemate tyria [satyria?] dicitur. Qui morbi cum in corpore eminuerint, maximum periculum necesse est faciant. Quidam tamen eorum maxime in cerebro dominantur, quidam vero in corpore solo et quidam in utroque. Sunt et alii in quibus membris sicut in manibus, pedibus quoque et similibus.

Et quidam pilos deponuntur, quidam vero non; alii carnem consumunt, alii et pruriginem et scabiem pariunt et furfures, alii morfeas nigras sive rufas seu albas, alii impetiginem latam gignunt, nigram quoque et pessimam. Quidam et cutem crepant et eam reddunt fluidam, alii non; quidam et ungulas deponunt et quidam corpus desiccant totum.