he looked down at the small volume and opened it to the first , crumbling page , at words written in faded ink : ala-al-din abu al-hassan ali ibn abi-hazm al-qarshi al-dimashqi ibn al- nafis commentary on the anatomy of canon of avicenna he turned to another page and read : the blood from the right chamber of the heart must arrive at the left chamber but there is no direct pathway between them .