Abstract
This paper presents some of Santorio's marginalia to his Commentaria in primam fen primi libri Canonis Avicennae (Venice, 1625), which I identified in the Sloane Collection of the British Library in 2016, as well as the evidence for their authorship. The name of the Venetian physician Santorio Santori (1561-1636) is linked with the introduction of quantification in medicine and with the invention of precision instruments that, displayed for the first time in this work, laid down the foundations for what we today understand as evidence-based medicine. But Santorio's monumentale opus also contains evidence of many quantified experiments and displays his ideas on mixtures, structure of matter and corpuscles, which are in many cases clarified and completed by the new marginalia. These ideas testify to an early interest in chemistry within the Medical School of Padua which predates both Galileo and Sennert and which has hitherto been unknown.