This article contains the biography of the prominent French medical doctor and historian of medicine Lucien Nicolas Leclerc (1816–1893) as well as interpreted Latin transliterations of Arabic and Greek names of medicinal herbs and proper nouns, left by Leclerc in the margins of his copy of the Latin translation of De simplicibus medicinis by Yuhanna ibn Sarabiyun, who lived in the 9th century AD. This interpretation shows the stages of transformation of Greek nouns in the process of transliteration from Greek into Syrian, from Syrian to Arabic and subsequently from Arabic into Latin