alchemyyoudaoicibaDictYouDict[alchemy 词源字典]
alchemy: [14] Alchemy comes, via Old French alkemie and medieval Latin alchimia, from Arabic alkīmīā. Broken down into its component parts, this represents Arabic al ‘the’ and kīmīā, a word borrowed by Arabic from Greek khēmíā ‘alchemy’ – that is, the art of transmuting base metals into gold. (It has been suggested that khēmīā is the same word as Khēmīā, the ancient name for Egypt, on the grounds that alchemy originated in Egypt, but it seems more likely that it derives from Greek khūmós ‘fluid’ – source of English chyme [17] – itself based on the verb khein ‘pour’).

Modern English chemistry comes not directly from Greek khēmíā, but from alchemy, with the loss of the first syllable.
=> chemistry, chyme[alchemy etymology, alchemy origin, 英语词源]
alchemy (n.)youdaoicibaDictYouDict
mid-14c., from Old French alchimie (14c.), alquemie (13c.), from Medieval Latin alkimia, from Arabic al-kimiya, from Greek khemeioa (found c.300 C.E. in a decree of Diocletian against "the old writings of the Egyptians"), all meaning "alchemy." Perhaps from an old name for Egypt (Khemia, literally "land of black earth," found in Plutarch), or from Greek khymatos "that which is poured out," from khein "to pour," related to khymos "juice, sap" [Klein, citing W. Muss-Arnolt, calls this folk etymology]. The word seems to have elements of both origins.
Mahn ... concludes, after an elaborate investigation, that Gr. khymeia was probably the original, being first applied to pharmaceutical chemistry, which was chiefly concerned with juices or infusions of plants; that the pursuits of the Alexandrian alchemists were a subsequent development of chemical study, and that the notoriety of these may have caused the name of the art to be popularly associated with the ancient name of Egypt. [OED]
The al- is the Arabic definite article, "the." The art and the name were adopted by the Arabs from Alexandrians and thence returned to Europe via Spain. Alchemy was the "chemistry" of the Middle Ages and early modern times; since c. 1600 the word has been applied distinctively to the pursuit of the transmutation of baser metals into gold, which, along with the search for the universal solvent and the panacea, were the chief occupations of early chemistry.