There are two main views on the derivation of the Greek word.  According to one, the word comes from the greek χημεία, pouring, infusion, used in connexion with the study of the juices of plants, and thence extended to chemical manipulations in general; this derivation accounts for the old-fashioned spellings "chymist" and "chymistry". The other view traces it to khem or khame, hieroglyph khmi, which denotes black earth as opposed to barren sand, and occurs in Plutarch as χημεία; on this derivation alchemy is explained as meaning the "Egyptian art". The first occurrence of the word is said to be in a treatise of Julius Firmicus, an astrological writer of the 4th century, but the prefix al there must be the addition of a later Arabic copyist.  In English, Piers Plowman (1362) contains the phrase "experimentis of alconomye", with variants "alkenemye" and " alknamye". The prefix al began to be dropped about the middle of the 16th century (further details of which are given below).