Bar-Ilan University
Parashat Vayakhel-Pekudei 5772/March 23, 2012
Parashat Hashavua Study Center
Lectures on the weekly Torah reading by the faculty of Bar-Ilan University in Ramat Gan, Israel. A
project of the Faculty of Jewish Studies, Paul and Helene Shulman Basic Jewish Studies Center, and the
Office of the Campus Rabbi. Published on the Internet under the sponsorship of Bar-Ilan University's
International Center for Jewish Identity. Prepared for Internet Publication by the Computer Center
Staff at Bar-Ilan University.
904
Zekhariah Dori1
Purple Dye – Its Derivation and Use
Argaman in Hebrew, argamanna in Akkadian, argevan-argina in Aramaic and arjiwan in
Arabic refers to a shade of purple. In general, color is perceived by the eye because an
object absorbs certain wavelengths in the visible range of the light spectrum while reflecting
others as a result of its chemical composition. One can see light refracted into its various
colors in the rainbow that appears on a rainy but sunlit day. One can also distinguish colors
from secondary sources:
Dyes that occur in the inanimate world: these include in various materials, such as copper
sulfate which is blue, iron oxides which are red or yellow, sulphur which is yellow and lead
sulfide, of which kohl,2 a powder used to paint the eyes,3 is comprised.
Dyes derived from plants: these include a red dye derived from rubia tinctorum, and indigo,
a blue dye, from Isatis tinctoria and Indigofera tinctoria. Yellow dyes are derived from
crocuses, saffron, walnut shells and pomegranate peels.
Dyes from the animal world: these can come from insects, as in the case of crimson4 is
derived from insects and various Coccoidea, or from mollusks, as in the shades of blue5 and
purple. The biblical crimson, blue and purple were derived only from the animal world, as
1
Zekhariah Dori is a Doctoral Student in the Department of Jewish History.
As we read of Jezebel: "She painted her eyes with kohl" (II Kings 9:30).
3
Zekhariah Dori, Ha-Pukh ve-haKofer—Ha-Kuhol ve-ha-Hineh, Jerusalem 1982.
4
Zehkariah Dori, Tola`at ha-Shani, Kermiz ve-Kermil, Jerusalem 1996.
5
Menahem Borstein, Ha-Tekhelet, Jerusalem 1988.
2
1
we read in the Talmud, "Just as the crimson worm is something that has life, so too, anything
that has the breath of life" (Jerusalem Talmud, Kilaim 9.1).
The ancients defined colors metaphorically. Many expressions appear in Song of Songs
describing the beloved and the lover in color metaphors: "His lips are like lilies" (Song 5:13);
"Your lips are like a crimson thread" (Song 4:3); "His locks are curled and black as a raven"
(Song 5:11); as well as "The locks of your head are like purple" (Song 7:6). Midrash Ha-Gadol
says: "Blue refers to the sinews, purple to the flesh, and the crimson worm is the blood" (on
Ex. 25:3). And Enoch says: "There appeared to me two extremely large men…the look of
their legs like purple" (Enoch, vol. 2, ch. 1, 4-5). Biblical sources either were not familiar with
or simply did not mention many of the different hues known to us today, such as what we
call blue. The word tzeva (rendered here as dye or color) appears only once in Scripture, in
Judges, along with the expression "spoil of dyed cloths" (Judges 5:30).
The 2nd-century historian Julius Pollux6 cites a Greek legend about the discovery of the first
purple dye. Melqart, the god of Tyre, went out for a walk with his dog along the shore near
his city. Suddenly the dog bit a shell, and mucus stuck to his mouth. He wiped his dog's
mouth with his handkerchief, and it turned a brilliant red. He realized that it was not blood
and that the mucus of the snail could be used to dye fabric. A coin from the city of Tyre
dating to the third century shows a dog biting a snail, apparently a reflection of this story.
Archaeological findings from the areas where purple dye was produced reveal three kinds of
mollusks in the Mediterranean Sea and in various other maritime parts of the world that
were good for this purpose. The different types are:
1. Thais haemastoma (Purpura haemastoma), which is found at a depth of one meter
beneath the sea. This shell has a large opening and its color is red, hence its name.
2. (Murex trunculus) Phyllonotus trunculus, which abounds close to the seashore at a depth
of several meters beneath the sea.
3. (Murex brandaris) Bolinus brandaris – a snail found at a depth of several tens of meters
beneath the sea, identified by the long point on its shell.
6
Pollux, J., Onomasticon, 1:45-48.
2
Descriptions of how purple dye was derived from mollusks appear in Vetruvius7 and Pliny,8
as well as in Jewish sources: "Yogvim (husbandmen)—this refers to those who catch snails
from the promontory of Type as far as Haifa (Shabbat 16a); "Our Rabbi taught: he who
catches a purple-fish (hillazon or snail) and crushes it is not liable but for one [sinoffering]…he crushed it when [already] dead" (Shabbat 75a). Similarly, in Tractate Megillah
6a:
Zebulun said to the Holy One, blessed be He: Lord of the Universe, to my
brothers You gave fields and vineyards, and to me You gave hills and
valleys…He said to him: They all have need of you on account of the snail, as
it is said, "and the hidden hoards of the sand" (Deut. 33:19). Rabbi Joseph
taught: hoards refers to snails.
From these sources we learn that the snails from which purple dye was obtained could be
found in the territory of Zebulun, and the dye was extracted from them by crushing.
Purple snail hunting
Generally snails were caught by putting out wicker baskets containing bait, and sometimes
they were transferred to pools of water and raised like fish in a pond. Snails are caught in
the summer months, after they have mated, laid their eggs and hatched their eggs in the
spring.
The purple-producing mollusks all have a shell made of calcium and hypobranchial glands
that secrete a fluid which, when it comes into contact with the air, oxidizes and takes on a
purple color. When the gland is removed the snail dies. A certain snail living on the shores
of America can be stimulated to secrete the dye without the snail being killed.
Chemical structure
The Viennese professor, Dr. Friedlander, analyzed the purple dye from snails in the
beginning of the 20th century. He discovered that the chemical structure of the fluid
secreted by the gland is a four-ring carbon-based compound, the two central rings being
doubly bonded to two carbon atoms. This structure contains two nitrogen atoms, two
oxygen, and two bromine atoms, one in each ring (except for the central one). Indigo dye
differs in that it contains hydrogen instead of bromine, and therefore the purple is called
6,6'-dibromoindigo. Sometimes the fluid in the snails contains only one bromine atom,
resulting in colors ranging from purple to indigo. When the substance is exposed to air
oxidation occurs, forming two hydroxyl groups which cause the purple color to appear.
There is nothing coincidental about the colors tekhelet (blue) and argaman (purple)
appearing as a pair in Scripture,9 since both are derived from the same source: mollusks.
7
Vitruvius, On Architecture VII 13.1-3.
Pliny the Elder, Natural History IX.60-65.
9
Blue and purple are grouped together by the cantillation signs, separately from crimson, because the
former two are derived from snails, the latter from insects.
8
3
Their chemical structure is also similar, with the possibility of a transition from one color to
the other. But shani (crimson) comes from the crimson worm, an insect, and the quality of
this dye depends on the concentration of the material and the quality of its production.
Deriving the dye
After catching the snails and breaking their shells the glands are removed. Since the
substance in them is not soluble in water, it is soaked in an alkaline reducing solution
(opposite of oxidation). Fiber or fabric is placed in the colorless solution. The fluid from the
gland combines with the fiber or fabric. When the fabric is exposed to oxygen in the air
oxidation takes place, creating the purple color. Ancient epigraphical sources, archaeological
findings and modern laboratory research all attest to this method of producing the color.
Archaeological findings
Discoveries include broken shells, fragments of dishes in which purple color has been
preserved, dyed fabrics and remains of manufacturing installations. Most of the findings
come from the shores of ancient Phoenicia10 and Israel, primarily from Acre, Tel Kabri,
Shikmona, Tyre, Caesarea, Apollonia,11 Tel Mor and around Ashdod.
Purple garments
Wool fiber takes well to purple dye. Fabrics dyed purple were expensive and hence were
not possessed by the common folk but were the garb of priests, kings, Roman emperors and
leaders of the Church. Argaman refers to wool that is dyed red (Midrash ha-Gadol, Exodus
25.1).
In Scripture, purple is mentioned in the series of colors: "blue, purple and crimson" (Ex.
25:4). The screen for the entrance of the Tabernacle and the curtain in the Temple were
dyed with these three colors. Purple is also mentioned in connection with the garments of
the high priest—the ephod, the breastpiece, and the robe. A thread of gold was added to
some of these fabrics.
Fabric dyed exclusively purple was used to cover the altar in the Tabernacle, as we read:
"They shall remove the ashes from the altar and spread a purple cloth over it" (Num. 4:13).
Purple was deliberately chosen for covering the altar since it "is like fire" (Midrash ha-Gadol,
loc. cit.). According to the sources cited here, argaman has a color similar to that of fire and
blood.
As we said, purple is the color of kings.12 The Book of Maccabees says that Ptolemy, ruler of
Egypt, dressed Jonathan the Hasmonean in such a garment: "The king…gave orders for
Jonathan to be divested of the garment he wore and robed in purple" (I Maccabees 10:62).
In contrast, being divested of stature is marked by removing the purple garment: "In a
10
The seashore from Type to Sidon and northward.
Apollonia is also called Arsuf.
12
While the woman of valor in Proverbs 31 is not a queen, nevertheless she is described as wearing
fine linen and purple: "Her clothing is linen and purple" (v. 22).
11
4
burning fury, he immediately stripped Andronicus of the purple, tore off his clothes" (II
Maccabees 4:38).
Purple garments were considered valuable booty from battle: after Gideon's victory over
Zebah and Tzalmunna he demanded of his soldiers that they turn over the booty, which
included "golden earrings…in addition to the crescents and the pendants and the purple
robes worn by the kings of Midian" (Judges 8:26). Even Judas Maccabaeus plundered the
camp of Gorgias that lay in the valley, "and there they got much gold and silver, violet and
purple stuffs, and great riches" (I Maccabees 4:23).
Translated by Rachel Rowen
5