alchemy (n.) Look up alchemy at Dictionary.com
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.
alchemist (n.) Look up alchemist at Dictionary.com
1510s, from Middle French alquemiste, from Medieval Latin alchimista (see alchemy). Earlier forms were alchemister (late 14c.), alkanamyer (late 15c.).
alkahest (n.) Look up alkahest at Dictionary.com
"universal solvent sought by alchemists," 1640s, from French alcahest, from Medieval Latin alcahest, a pseudo-Arabic word coined by Paracelsus (see alchemy).
chemist (n.) Look up chemist at Dictionary.com
1560s, chymist, "alchemist," from Middle French chimiste, from Medieval Latin chimista, reduced from alchimista (see alchemy). Modern spelling is from c. 1790. Meaning "chemical scientist" is from 1620s; meaning "dealer in medicinal drugs" (mostly in British English) is from 1745.
alchemical (adj.) Look up alchemical at Dictionary.com
1580s; see alchemy + -ical.
chemical (adj.) Look up chemical at Dictionary.com
1570s, "relating to chemistry," from chemic "of alchemy" (a worn-down derivative of Medieval Latin alchimicus; see alchemy) + -al (1). In early use also of alchemy. Related: Chemically.
hermetic (adj.) Look up hermetic at Dictionary.com
1630s "dealing with occult science or alchemy," from Latin hermeticus, from Greek Hermes, god of science and art (among other things), who was identified by Neoplatonists, mystics, and alchemists with the Egyptian god Thoth as Hermes Trismegistos "Thrice-Great Hermes," who supposedly invented the process of making a glass tube airtight (a process in alchemy) using a secret seal. Hence, "completely sealed" (c. 1600, implied in hermetically).
projection (n.) Look up projection at Dictionary.com
late 15c., in alchemy, "transmutation by casting a powder on molten metal; 1550s in the cartographical sense "drawing of a map or chart according to scale," from Middle French projection, from Latin proiectionem (nominative proiectio), from past participle stem of proicere (see project (n.)). From 1590s as "action of projecting."
fermentation (n.) Look up fermentation at Dictionary.com
late 14c., in alchemy, with a broad sense; modern scientific sense is from c. 1600; from Late Latin fermentationem (nominative fermentatio), noun of action from past participle stem of Latin fermentare "to ferment" (see ferment (v.)). Figurative use attested from 1650s.
sublimation (n.) Look up sublimation at Dictionary.com
late 14c., in alchemy, "process of purifying by vaporizing then allowing to cool," from Medieval Latin sublimationem (nominative sublimatio) "refinement," literally "a lifting up, deliverance," noun of action from past participle stem of Latin sublimare "to raise, elevate," from sublimis "lofty, high, exalted; eminent, distinguished" (see sublime).
graduation (n.) Look up graduation at Dictionary.com
early 15c., in alchemy, "a tempering, a refining of something to a certain degree; measurement according to the four degrees of a quality," from graduate (n.). General sense of "a dividing into degrees" is from 1590s; meaning "action of receiving or giving an academic degree" is from early 15c.; in reference to the ceremony where a degree is given, from 1818.
chemistry (n.) Look up chemistry at Dictionary.com
c. 1600, "alchemy," from chemist + -ry; also see chemical (adj.). The meaning "natural physical process" is 1640s, and the scientific study not so called until 1788. The figurative sense of "instinctual attraction or affinity" is attested slightly earlier, from the alchemical sense.
transmutation (n.) Look up transmutation at Dictionary.com
late 14c., from Old French transmutacion "transformation, change, metamorphosis" (12c.), from Late Latin transmutationem (nominative transmutatio) "a change, shift," noun of action from Latin transmutare "change from one condition to another," from trans- "thoroughly" (see trans-) + mutare "to change" (see mutable). A word from alchemy.
practice (n.) Look up practice at Dictionary.com
early 15c., practise, "practical application," originally especially of medicine but also alchemy, education, etc.; from Old French pratiser, from Medieval Latin practicare (see practice (v.)). From early 15c. often assimilated in spelling to nouns in -ice. Also as practic, which survived in parallel into 19c.
occult (adj.) Look up occult at Dictionary.com
1530s, "secret, not divulged," from Middle French occulte and directly from Latin occultus "hidden, concealed, secret," past participle of occulere "cover over, conceal," from ob "over" (see ob-) + a verb related to celare "to hide," from PIE root *kel- (2) "to cover, conceal" (see cell). Meaning "not apprehended by the mind, beyond the range of understanding" is from 1540s. The association with the supernatural sciences (magic, alchemy, astrology, etc.) dates from 1630s.
glorification (n.) Look up glorification at Dictionary.com
early 15c. "admission to Heaven, exaltation" (theological), from Late Latin glorificationem (nominative glorificatio), noun of action from past participle stem of glorificare "to glorify" (see glorify). General sense by mid-19c. Also in 15c. as a term in alchemy, "action of refining; state of being refined." Gloriation "praising" is from c. 1400.
precipitation (n.) Look up precipitation at Dictionary.com
late 15c., "a casting down" (of the evil angels from heaven), also, in alchemy "separation of a solid substance from a solution," from Middle French precipitation (15c.) and directly from Latin praecipitationem (nominative praecipitatio) "act or fact of falling headlong, haste," noun of action from past participle stem of praecipitare "fall, be hasty," from praeceps "steep" (see precipice). Meaning "sudden haste" is c. 1500. Meaning "act of falling from a height" is attested from 1610s. Meteorological sense of "rain, snow, dew, etc." is from 1670s.
tertium quid (n.) Look up tertium quid at Dictionary.com
something indeterminate between two other things, 1724, Latin, literally "third something," from tertius "third, a third," from the root of tres "three" (see three). A loan-translation of Greek triton ti (Plato), used in alchemy for "unidentified element present in a combination of two known ones." The Latin word also figures in phrases tertium non datur "no third possibility exists," and tertius gaudens "a third party that benefits from conflict between the other two."
pseudo-science (n.) Look up pseudo-science at Dictionary.com
also pseudoscience, "a pretended or mistaken science," 1796 (the earliest reference is to alchemy), from pseudo- + science.
The term pseudo-science is hybrid, and therefore objectionable. Pseudognosy would be better etymology, but the unlearned might be apt to association with it the idea of a dog's nose, and thus, instead of taking "the eel of science by the tail," take the cur of science by the snout; so that all things considered we had better adopt the current term pseudo-sciences ["The Pseudo-Sciences," in "The St. James Magazine," January 1842]
quintessence (n.) Look up quintessence at Dictionary.com
early 15c., in ancient and medieval philosophy, "pure essence, substance of which the heavenly bodies are composed," literally "fifth essence," from Middle French quinte essence (14c.), from Medieval Latin quinta essentia, from Latin quinta, fem. of quintus "fifth" (see quinque-) + essentia (see Parousia).

A loan-translation of Greek pempte ousia, the "ether" added by Aristotle to the four known elements (water, earth, fire, air) and said to permeate all things. Its extraction was one of the chief goals of alchemy. Sense of "purest essence" (of a situation, character, etc.) is first recorded 1580s.
mercury (n.) Look up mercury at Dictionary.com
silver-white fluid metallic element, late 14c., from Medieval Latin mercurius, from Latin Mercurius (see Mercury). Prepared from cinnabar, it was one of the seven metals (bodies terrestrial) known to the ancients, which were coupled in astrology and alchemy with the seven known heavenly bodies. This one probably so associated for its mobility. The others were Sun/gold, Moon/silver, Mars/iron, Saturn/lead, Jupiter/tin, Venus/copper. The Greek name for it was hydrargyros "liquid silver," which gives the element its symbol, Hg. Compare quicksilver.
spermaceti (n.) Look up spermaceti at Dictionary.com
"waxy, fatty stuff in the head of certain whales," late 15c., from Medieval Latin sperma ceti "sperm of a whale" (it has when fresh something of the appearance of sperm), from Latin sperma "seed, semen" (see sperm) + ceti, genitive of cetus "whale, large sea animal" (see Cetacea). The substance in olden times was credited with medicinal properties, as well as being used for candle oil.
Use ... Sperma Cete ana with redd Wyne when ye wax old. [Sir George Ripley, "The Compound of Alchemy," 1471]
Scientists still are not sure exactly what it does. Sperm whale, short for spermaceti whale, is from 1830.
philosopher (n.) Look up philosopher at Dictionary.com
from Old English philosophe, from Latin philosophus "philosopher," from Greek philosophos "philosopher, sage, one who speculates on the nature of things and truth," literally "lover of wisdom," from philos "loving" (see -phile) + sophos "wise, a sage" (see sophist). Modern form with -r appears early 14c., from an Anglo-French or Old French variant of philosophe, with an agent-noun ending.
Pythagoras was the first who called himself philosophos, instead of sophos, 'wise man,' since this latter term was suggestive of immodesty. [Klein]
Philosophy also was used of alchemy in Middle Ages, hence Philosophers' stone (late 14c., translating Medieval Latin lapis philosophorum, early 12c.), a reputed solid substance supposed by alchemists to change baser metals into gold or silver; also identified with the elixir and thus given the attribute of prolonging life indefinitely and curing wounds and disease. (French pierre philosophale, German der Stein der Weisen).
magnesia (n.) Look up magnesia at Dictionary.com
late 14c., in alchemy, "main ingredient of the philosopher's stone," from Medieval Latin magnesia, from Greek (he) Magnesia (lithos) "the lodestone," literally "(the) Magnesian (stone)," from Magnesia, region in Thessaly, which is said to be named for the native people name Magnetes, which is of unknown origin. The ancient word, in this sense, has evolved into magnet. But in ancient times the same word, magnes, was used of lodestone as well as of a mineral commonly used in bleaching glass (modern pyrolusite, or manganese dioxide).

In Middle Ages there was some attempt to distinguish lodestone as magnes (masc.) and pyrolusite as magnesia (fem.). Meanwhile, in 18c., a white powder (magnesium carbonate) used as a cosmetic and toothpaste was sold in Rome as magnesia alba ("white magnesia"). It was from this, in 1808, that Davy isolated magnesium. He wanted to call it magnium, to stay as far as possible from the confused word magnesia, but the name was adopted in the form magnesium. Meanwhile from 16c. the other name of pyrolusite had been corrupted to manganese, and when, in 1774, a new element was isolated from it, it came to be called manganese.

Magnesia in its main modern sense of "magnesium oxide" (1755) is perhaps an independent formation from Latin magnes carneus "flesh-magnet" (c. 1550), so called because it adheres strongly to the lips.
spirit (n.) Look up spirit at Dictionary.com
mid-13c., "animating or vital principle in man and animals," from Anglo-French spirit, Old French espirit "spirit, soul" (12c., Modern French esprit) and directly from Latin spiritus "a breathing (respiration, and of the wind), breath; breath of a god," hence "inspiration; breath of life," hence "life;" also "disposition, character; high spirit, vigor, courage; pride, arrogance," related to spirare "to breathe," perhaps from PIE *(s)peis- "to blow" (cognates: Old Church Slavonic pisto "to play on the flute"). But de Vaan says "Possibly an onomatopoeic formation imitating the sound of breathing. There are no direct cognates."

Meaning "supernatural immaterial creature; angel, demon; an apparition, invisible corporeal being of an airy nature" is attested from mid-14c.; from late 14c. as "a ghost" (see ghost (n.)). From c. 1500 as "a nature, character"; sense of "essential principle of something" (in a non-theological context, as in Spirit of St. Louis) is attested from 1680s, common after 1800; Spirit of '76 in reference to the qualities that sparked and sustained the American Revolution is attested by 1797 in William Cobbett's "Porcupine's Gazette and Daily Advertiser."

From late 14c. in alchemy as "volatile substance; distillate;" from c. 1500 as "substance capable of uniting the fixed and the volatile elements of the philosopher's stone." Hence spirits "volatile substance;" sense narrowed to "strong alcoholic liquor" by 1670s. This also is the sense in spirit level (1768). Also from mid-14c. as "character, disposition; way of thinking and feeling, state of mind; source of a human desire;" in Middle English freedom of spirit meant "freedom of choice." From late 14c. as "divine substance, divine mind, God;" also "Christ" or His divine nature; "the Holy Ghost; divine power;" also, "extension of divine power to man; inspiration, a charismatic state; charismatic power, especially of prophecy." Also "essential nature, essential quality." From 1580s in metaphoric sense "animation, vitality."

According to Barnhart and OED, originally in English mainly from passages in Vulgate, where the Latin word translates Greek pneuma and Hebrew ruah. Distinction between "soul" and "spirit" (as "seat of emotions") became current in Christian terminology (such as Greek psykhe vs. pneuma, Latin anima vs. spiritus) but "is without significance for earlier periods" [Buck]. Latin spiritus, usually in classical Latin "breath," replaces animus in the sense "spirit" in the imperial period and appears in Christian writings as the usual equivalent of Greek pneuma. Spirit-rapping is from 1852.