Editing Tyrian purple (section)

==Background==
[[File:Mosaic of Justinianus I - Basilica San Vitale (Ravenna).jpg|thumb|Byzantine Emperor [[Justinian I]] clad in Tyrian purple, 6th-century mosaic at [[Basilica of San Vitale]], [[Ravenna]], [[Italy]]]]

The [[colour fastness|colour-fast]] (non-fading) dye was an item of luxury trade, prized by [[ancient Rome|Romans]], who used it to colour [[toga|ceremonial robes]]. Used as a dye, the colour shifts from blue (peak absorption at 590&nbsp;nm, which is yellow-orange) to reddish-purple (peak absorption at 520&nbsp;nm, which is green).<ref>{{cite journal |vauthors=Cooksey CJ |title=Tyrian purple: 6,6'-dibromoindigo and related compounds |journal=Molecules |year=2001 |volume=6 |issue=9 |pages=736–769 |pmc=6236399 |doi=10.3390/60900736 |doi-access=free}}</ref> It is believed that the intensity of the purple hue improved rather than faded as the dyed cloth aged. [[Vitruvius]] mentions the production of Tyrian purple from shellfish.<ref>{{cite book |author=Vitruvius |title=De Architectura |trans-title=On Architecture |url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Vitruvius/7*.html |at=Book VII, Chapter 13}}</ref> In his ''[[History of Animals]]'', [[Aristotle]] described the shellfish from which Tyrian purple was obtained and the process of extracting the tissue that produced the dye.<ref>{{cite book |author=Aristotle |title=History of Animals |location=Whitefish, MT |publisher=Kessering Publishing |year=2004 |at=Book&nbsp;V, pages&nbsp;131–132 |url=https://books.google.com/books?id=Dma7o9N6zWkC&q=stains&pg=PA132 |isbn=9781419123917}}</ref> [[Pliny the Elder]] described the production of Tyrian purple in his ''[[Natural History (Pliny)|Natural History]]'':<ref>{{cite book |author=Pliny the Elder |title=The Natural History |editor1-link=John Bostock (physician) |veditors=Bostock J, Riley HT |editor2-link=Henry Thomas Riley |location=London, UK |publisher=Taylor and Francis |year=1855 |at=Book IX |chapter=Chapter&nbsp;62: ''The Natural History of Fishes'' |chapter-url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0137%3Abook%3D9%3Achapter%3D62}} Pliny discusses Tyrian purple throughout Chapters&nbsp;60–65.</ref><ref group=lower-alpha>The problem with Tyrian purple is that the precursor reacts very quickly with air and light to form an insoluble dye. (Hence Pliny says: "...&nbsp;''when [the shellfish] have once discharged their waxy secretion, their juices have no consistency''.&nbsp;...") The cumbersome process that Pliny describes is necessary to reverse the oxidation and to restore the water-soluble precursor so that large masses of wool can be dyed. See: {{cite journal |vauthors=Biggam CP |year=2006 |title=Knowledge of whelk dyes and pigments in Anglo-Saxon England |journal=Anglo-Saxon England |volume=35 |at=pages&nbsp;23–56; see especially pages&nbsp;26–27 |url=https://books.google.com/books?id=ZojyGIfG9m4C&q=soluble+insoluble&pg=PA26 |isbn=9780521883429 |doi=10.1017/S0263675106000032 |s2cid=162937239}} See also: C. J. Cooksey (2001) "Tyrian purple: 6,6'-Dibromoindigo and Related Compounds", ''Molecules'', '''6''' (9) : 736–769, especially page 761. Indigo, which is chemically very similar to Tyrian purple, behaves similarly. See: http://www.indigopage.com/chemistry.htm</ref>

<blockquote>The most favourable season for taking these [shellfish] is after the rising of the [[Sirius|Dog-star]], or else before spring; for when they have once discharged their waxy secretion, their juices have no consistency: this, however, is a fact unknown in the dyers' workshops, although it is a point of primary importance. After it is taken, the vein [i.e. hypobranchial gland] is extracted, which we have previously spoken of, to which it is requisite to add salt, a sextarius [about 20&nbsp;fl.&nbsp;oz.] to every hundred pounds of juice. It is sufficient to leave them to steep for a period of three days, and no more, for the fresher they are, the greater virtue there is in the liquor. It is then set to boil in vessels of tin [or lead], and every hundred amphorae ought to be boiled down to five hundred pounds of dye, by the application of a moderate heat; for which purpose the vessel is placed at the end of a long funnel, which communicates with the furnace; while thus boiling, the liquor is skimmed from time to time, and with it the flesh, which necessarily adheres to the veins. About the tenth day, generally, the whole contents of the cauldron are in a liquefied state, upon which a fleece, from which the grease has been cleansed, is plunged into it by way of making trial; but until such time as the colour is found to satisfy the wishes of those preparing it, the liquor is still kept on the boil. The tint that inclines to red is looked upon as inferior to that which is of a blackish hue. The wool is left to lie in soak for five hours, and then, after carding it, it is thrown in again, until it has fully imbibed the colour.</blockquote>

Archaeological data from [[Tyre, Lebanon|Tyre]] indicate that the snails were collected in large vats and left to decompose. This produced a hideous stench that was mentioned by ancient authors. Not much is known about the subsequent steps, and the actual ancient method for mass-producing the two murex dyes has not yet been successfully reconstructed; this special "blackish clotted blood" colour, which was prized above all others, is believed to be achieved by double-dipping the cloth, once in the indigo dye of ''H.&nbsp;trunculus'' and once in the purple-red dye of ''B.&nbsp;brandaris''.<ref name=Pigments_WebExhibits/><ref name=Moorey1999/>

[[File:Theodoor van Thulden - The Discovery of Purple.jpg|thumb|''[[Hercules' Dog Discovers Purple Dye|The Discovery of Purple by Hercules's Dog]]'' by [[Theodoor van Thulden]], c.&nbsp;1636]]
[[File:OldGreekPhoenikianCoinPurpur2000.jpg|thumb|A [[Phoenicia]]s coin depicting the legend of the dog biting the sea snail]]

The Roman [[mythographer]] [[Julius Pollux]], writing in the 2nd&nbsp;century&nbsp;AD, recounts that the purple dye was first discovered by [[Heracles]] (Greek counterpart of the titular god of Tyre, Melqart){{Efn|Melqart was equated with Heracles in Greek sources because both deities shared roles as heroic figures linked to strength, protection, and the founding of cities, which led to an ''[[interpretatio graeca]]''—a Greek practice of identifying foreign gods with their own.<ref>{{Cite book |last=Hornblower |first=Simon |url=https://www.google.nl/books/edition/The_Oxford_Classical_Dictionary/bVWcAQAAQBAJ |title=The Oxford Classical Dictionary |last2=Spawforth |first2=Antony |last3=Eidinow |first3=Esther |date=2012 |publisher=OUP Oxford |isbn=978-0-19-954556-8 |pages=664 |language=en}}</ref><ref>{{Cite journal |last=Lichtenberger |first=Achim |date=2022-12-15 |title=The Youthful Heracles-Melqart in Tyre. Choosing a Visual Language for a Phoenician God in the Hellenistic Period |url=https://journals.openedition.org/mythos/5419 |journal=Mythos. Rivista di Storia delle Religioni |language=en |issue=16 |doi=10.4000/mythos.5419 |issn=1972-2516|doi-access=free }}</ref>}} while being in Tyre to visit his beloved [[Tyros (nymph)|Tyros]], or rather, by his dog, whose mouth was stained purple after biting into a snail on the beach.<ref>{{Cite book |last=Pollux |first=Julius |url=https://archive.org/details/onomasticon01polluoft/page/n125/mode/2up |title=Onomasticon |last2=Dindorf |first2=Wilhelm |date=1824 |publisher=Leipzig : Kuehn |others=Robarts - University of Toronto |page=16 (at 45–49) |orig-date=Second century AD}}</ref> This story was depicted by [[Peter Paul Rubens]] in his painting ''[[Hercules' Dog Discovers Purple Dye]]''. According to [[John Malalas]], the incident happened during the reign of the legendary [[Phoenix (son of Agenor)|King Phoenix of Tyre]], the eponymous progenitor of the Phoenicians, and therefore he was the first ruler to wear Tyrian purple and legislate on its use.<ref>John Malalas, ''Chronographia'' II:9.</ref>

Recently, the archaeological discovery of substantial numbers of Murex shells on [[Crete]] suggests that the [[Minoans]] may have pioneered the extraction of Imperial purple centuries before the Tyrians. Dating from collocated pottery suggests the dye may have been produced during the Middle Minoan period in the 20th–18th&nbsp;century&nbsp;BC.<ref>Reese, David S. (1987). "Palaikastro Shells and Bronze Age Purple-Dye Production in the Mediterranean Basin", ''Annual of the British School of Archaeology at Athens'', '''82''', 201–206</ref><ref>Stieglitz, Robert R. (1994), "The Minoan Origin of Tyrian Purple", ''Biblical Archaeologist'', '''57''', 46–54.</ref> Accumulations of crushed murex shells from a hut at the site of [[Coppa Nevigata]] in southern Italy may indicate production of purple dye there from at least the 18th&nbsp;century&nbsp;BC.<ref>{{cite book |vauthors=Cazzella A, Moscoloni M |year=1998 |article=Coppa Nevigata: un insediamento fortificato dell'eta del Bronzo |veditors=Troccoli LD |title=Scavi e ricerche archeologiche dell'Università di Roma La Sapienza |url=https://books.google.com/books?id=Zcc5P5hqsu8C&pg=PA178 |pages=178–179 |publisher=L'ERMA di BRETSCHNEIDER |isbn=9788882650155}}</ref> Additional archaeological evidence can be found from samples originating from excavations at the extensive Iron Age copper smelting site of “Slaves’ Hill” (Site 34), which is tightly dated by radiocarbon to the late 11th–early 10th centuries BC.<ref name=NS/> Findings from this site include evidence of the use of purple dye found in stains used on pot shards. Evidence of the use of dye in pottery are found in most cases on the upper part of ceramic basins, on the inside surface, the areas in which the reduced dye-solution was exposed to air, and underwent oxidation that turned it purple.<ref name=NS/>

The production of ''Murex'' purple for the Byzantine court came to an abrupt end with the [[Siege of Constantinople (1204)|sack of Constantinople in 1204]], the critical episode of the [[Fourth Crusade]]. David Jacoby concludes that "no Byzantine emperor nor any Latin ruler in former Byzantine territories could muster the financial resources required for the pursuit of murex purple production. On the other hand, murex fishing and dyeing with genuine purple are attested for Egypt in the tenth to 13th centuries."<ref>Jacoby (2004), p.&nbsp;210.</ref> By contrast, Jacoby finds that there are no mentions of purple fishing or dyeing, nor trade in the colorant in any Western source, even in the Frankish Levant. The European West turned instead to [[vermilion]] provided by the insect ''[[Kermes vermilio]]'', known as ''grana'', or [[crimson]].

In 1909, Harvard anthropologist [[Zelia Nuttall]] compiled an intensive comparative study on the historical production of the purple dye produced from the carnivorous [[murex snail]], source of the [[royal purple]] dye valued higher than gold in the ancient Near East and ancient Mexico. Not only did the people of ancient Mexico use the same methods of production as the Phoenicians, they also valued murex-dyed cloth above all others, as it appeared in codices as the attire of nobility. "Nuttall noted that the Mexican murex-dyed cloth bore a "disagreeable ... strong fishy smell, which appears to be as lasting as the color itself."<ref>{{cite book |vauthors=Nutall Z |chapter=A curious survival in Mexico of the use of the Purpura shell-fish for dyeing |veditors=Boas F |title=Anthropological Essays Presented to Fredrick Ward Putnam in Honor of his Seventieth Birthday, by his Friends and Associates |publisher=G. E. Strechert & Co. |location=New York, New York |date=1909 |chapter-url=https://babel.hathitrust.org/cgi/pt?id=njp.32101079830103;view=1up;seq=460 |page=370}}</ref> Likewise, the ancient Egyptian ''Papyrus of Anastasi'' laments: "The hands of the dyer reek like rotting fish".<ref name="robinson">{{cite book |vauthors=Robinson S |title=A History of Dyed Textiles |date=1969 |publisher=Studio Vista |location=London, UK |page=24}}</ref> So pervasive was this stench that the [[Talmud]] specifically granted women the right to divorce any husband who became a dyer after marriage.<ref>{{cite book |vauthors=Compton S |title=Exodus Lost |date=2010 |publisher=Booksurge Publishing |isbn=9781439276839 |pages=29–33 |edition=1st |url=https://books.google.com/books?isbn=1439276838}}</ref>

In 2021, archaeologists found surviving wool fibers dyed with royal purple in the [[Timna Valley]] in Israel. The find, which was dated to {{Circa|1000 BC}}, constituted the first direct evidence of fabric dyed with the pigment from antiquity.<ref>{{cite journal |last1 = Sukenik |first1=Naama |last2 = Iluz |first2 = David |last3 = Amar |first3 = Zohar |last4 = Varvak |first4 = Alexander |last5 = Shamir |first5 = Orit |last6 = Ben-Yosef |first6 = Erez |date = January 2021 |title = Early evidence of royal purple dyed textile from Timna Valley (Israel) |journal = PLOS ONE |volume = 16 |issue=1 |pages = e0245897 |doi = 10.1371/journal.pone.0245897|doi-access=free |pmid=33507987 |pmc=7842898 |bibcode=2021PLoSO..1645897S }}</ref>