Note 1686 — Chapter LVIII
Reading edition
“Oportet quod medicina simplex experiatur in duabus contrariis aegritudinibus diversis, sicut scamonea in quotidiana et tertiana, ipsa enim curat quotidianam ex sua complexione, tertianam ex proprietate sua, tamen non sequitur, scamonea curat tertianam, ergo est frigida; sed sequitur, ipsa ex sua complexione curat quotidianam, ergo est calida.”
The use of the word “proprietas” for occult virtue is found also in Arnald of Villanova and other medieval writers.