De Gradibus is the Latinized name of the Arabic book published by the Arab physician Al-Kindi (c. 801–873 CE). De gradibus is the Latinized name of the book.
In De Gradibus, Al-Kindi attempts to apply mathematics to pharmacology by quantifying the strength of drugs. According to Prioreschi, this was the first attempt at serious quantification in medicine. He also developed a system, based on the phases of the Moon, that would allow the doctors to determine in advance the most critical days of a patient’s illness.
