Mendel Singer’s Reply to Baruch Sterman Re: Understanding the Criteria of the Chilazon

I would like to thank Dr. Sterman for agreeing to respond to my article, thereby affording the readers both sides of the story. I would also like to thank the editor, Rabbi Cohen, for devoting so much space to this issue. In fairness to the editor I will endeavor to be brief, while trying to cover most of the essential points.

Criteria from the sugya of techeilet

Dr. Sterman prefaces his comments with the rather startling assertion that we can essentially ignore the descriptions brought by Chazal in Menachot (44a) because many Rishonim do not cite these criteria or omit one of them. There is only one sugya in the entire Talmud that deals explicitly with the details of techeilet. Nowhere else in the Talmud do Chazal cite statements for the primary purpose of describing the chilazon. How can these statements of Chazal not be important? Dr. Sterman has said that the writings of the Radzyner Rebbe and Rabbi Herzog must form the foundation of any halachic discussion of techeilet. These criteria are the heart of Rabbi Herzog’s criteria, essential to the Radzyner Rebbe’s criteria, and have been considered of unquestioned importance even in most, if not all prior writings by supporters of the murex trunculus theory. How can Dr. Sterman now claim they are not essential?

While horns are not essential to the halachot of the burnt offering brought by the Kohen Gadol on Yom Kippur, that animal must be a ram, and would, therefore, have horns. Similarly, it is not surprising that when writing about techeilet, some Rishonim may mention that techeilet must come from a chilazon without describing the chilazon.

Nonetheless, the chilazon must possess the characteristics that Chazal have ascribed to it. Rashi brings down all of these criteria in multiple places, and it would be presumptuous to assume that those who omit one (“rises once in seventy years”) did so because they felt it could be ignored. Indeed, the Radzyner Rebbe explains why some omit the seventy year criterion.¹ Let us briefly examine these criteria.

“Its body resembles the sea”: Dr. Sterman’s argument as to how murex trunculus meets these criteria is based on three false premises, namely, that the expression domeh l’yam can mean green, that the expression gufo (“its body”) can refer to external organisms living on the shell of the chilazon, and that the resemblance is to the living organisms in the sea and not the sea itself. Regarding domeh l’yam, the same expression is used just a few lines earlier in the Gemara to refer to the color of techeilet. Dr. Sterman is asserting that “resembles the sea” can mean blue in one phrase and a few lines later, dealing with the same subject, mean green. This is both illogical and groundless.

Rambam clearly indicates otherwise since he writes that the chilazon itself resembles techeilet, i.e. blue.² Similarly, the braita of tzitzit states that the color of the body of the chilazon is similar to the sky.³ Dr. Sterman suggests gufo cannot mean the soft body since it would be impractical to describe the color of the body which can only be viewed by the careful breaking of the shell and extraction of the soft body. Of course, this presupposes the chilazon is completely enclosed by a hard exterior shell. Also, it would only be necessary to check the color of the body to identify the correct species. It would not be necessary to check every animal that is used. While Dr. Sterman’s claim that gufo could refer to the shell is not entirely unreasonable, it is quite a different matter to say that “its body” means the external organisms covering the shell. Whereas it would indeed make sense to describe the outward appearance, it would hardly be helpful to describe the external sea fouling if it looks like everything else.

While murex trunculus does blend in with its surroundings due to the greenish sea fouling, this means it resembles the sea fouling and plant life living in the sea, but not the sea itself.

“Its form is like a fish (dag)”: Dr. Sterman’s response is that according to halacha, murex trunculus is a fish, therefore this statement is true by definition. This renders meaningless the statement of Chazal. Why would Chazal say “the chilazon, which is a fish, resembles a fish”? Clearly the intent is to inform us that the form of the chilazon has some similarity to what is characteristically true of fish. No such argument can be made for the murex trunculus snail.

“Comes up once in seventy years”: Dr. Sterman admits that there is no characteristic of the murex trunculus that would meet this criterion. Dr. Sterman’s unfounded speculation about the replenishing of the snail population suggests a steady pattern of increase in the population and not an unusual abundance. Rabbi Herzog cites a 3-6 year cycle for his candidate species.⁴ As for the Radzyner Rebbe’s choice of sepia officinalis, since the Rebbe’s death a periodicity has been noted and there have been rare reports of mass “invasions” and “strandings” of cuttlefish.⁵

“It is expensive”: The Gemara states the dye is expensive because of the lack of abundance (“comes up once in 70 years”). One of the reasons Rabbi Herzog rejects murex trunculus is because of the minute dye quantity it produces.⁶ The Gemara clearly states that the reason techeilet is expensive is because of its infrequent appearance or abundance and not because of the minute dye           quantity. Dr. Sterman’s answer that a small village in Greece consumes 2 tons of snails in a week, enough for 10,000 sets of techeilet, is amusing, but merely underscores my point. That small village in Greece is eating the snail, not extracting the dye. Murex dye was not expensive due to scarcity but due to the work involved in extracting the dye from exceedingly large quantities of snails to produce small amounts of dye.

Chemical test for k’la Ilan

Rabbi Herzog, with the aid of renowned dye chemist Dr. A.C. Green, recognized that the Gemara’s tests have the aim of chemically reducing indigo. In this state indigo is yellow, thus the Gemara’s stipulation that if the color fades it fails the test and is suspected to be k’la ilan. Since snail indigo and plant indigo are the exact same chemical, murex indigo should also fail this test. Indeed, murex indigo would be expected to fail any chemical test that plant indigo fails, let alone the Gemara’s test which is clearly designed to detect indigo. Dr. Sterman posits that it is theoretically possible that some snail meat remaining in the murex indigo could keep it from failing the test. Since the Gemara’s test only requires the color to fade, not to be entirely reduced, the snail meat would have to completely inhibit the chemical reduction in order to pass the test. Dr. Sterman offers no reason why the snail meat might have this effect. In fact, the one statement he makes is that snail meat may have played an important role in aiding reduction. Dr. Sterman suggests that Nobel chemist Dr. Roald Hoffman has deemed his explanation plausible. I contacted Dr. Hoffman, and he merely maintains that the presence of bits of snail meat makes it theoretically possible to develop chemical tests to distinguish snail indigo from plant indigo, not that it was at all likely for the snail meat to have any impact in the chemical test of the Gemara. Even Dr. Irving Ziderman, the chemist who did so much of the pioneering work on the murex trunculus theory, acknowledges that snail indigo would fail this test.

Although Dr. Sterman says that he has recreated the Gemara’s tests and murex indigo passed, he then acknowledges that regular indigo also passed, thereby proving that he had not recreated the test correctly. It is my hope to accurately reproduce these tests and report the findings on my web site. ⁷ Thus we are left with sound scientific reason to suggest murex indigo would fail the Gemara’s tests versus the unfounded speculation that it is a theoretical possibility it would pass.

Other statements of Chazal regarding the chilazon

There are a number of descriptive comments made by Chazal which clearly do not describe murex trunculus and were not addressed by Dr. Sterman. Rambam, the Midrash HaGadol and Philo (who was alive when techeilet was made) state that the color of the blood of the chilazon is black, while Rashi states that the appearance of the blood is blue.⁸ When dyeing techeilet with murex indigo the dye solution is never blue. After wool is dipped in the dye vat, removed and exposed to air, the dyed wool turns blue. The Gemara also tells us that the chilazon was the source of a treatment for hemorrhoids, yet murex trunculus was known in ancient times to be bad for the bowels.⁹ The Mishnah in Keilim tells us that a metal hook attached to the “head” (roshoh) of a chain was called chilazon because of its shape, which the Radzyner Rebbe understands to mean that the chilazon has hook-shaped tentacles coming out of its head.¹⁰ Again, murex trunculus does not fit this description. Finally, we have the problem of why the Gemara, when choosing to describe the chilazon did not say that it was purpura? The species and its name were famous. Further, according to Josephus and others, it appears that murex snails were the source of argaman.¹¹ If so, why didn’t the Gemara state that the chilazon shel techeilet was from the same family of snails as that used for argaman?

Equivalence of murex techeilet with k’la ilan(indigo)

Dr. Sterman notes correctly that since murex techeilet is the same chemical as k’la ilan (plant indigo), its color is visually indistinguishable from plant indigo. He then makes the assertion that both the Radzyner Rebbe and Rabbi Herzog are of the opinion that if one finds a candidate for the chilazon that produces a dye that is sky-blue and is a fast dye, then it is automatically kosher techeilet. The statement from the Radzyner Rebbe is taken out of context.

The Rebbe concludes that section with the comment that it will be further explained in the following section, where the Rebbe states that the statements of Chazal must be satisifed, but if they are all satisfied and the dye meets the requirements then it is definitely kosher.¹² As for Rabbi Herzog, he places great importance on the criteria from Menachot. Rabbi Herzog states that the inquirer equipped with knowledge of the secular sources “will go to the Talmud only for a confirmation of the identification of the techeilet-species with murex trunculus. But there is a surprise in store for him”.¹³ Rabbi Herzog then dismisses murex trunculus because it fails to meet any of the criteria from the sugya in Menachot.¹⁴ As for the problem with the Gemara needing to warn us about murex indigo like it did for k’la ilan, this poses no difficulty for several reasons. First, the Gemara doesn’t need to warn us about anything that did not happen. Whereas counterfeiting techeilet with k’la ilan was a real problem, counterfeiting with murex indigo is a theoretical problem with no indication that murex trunculus was ever used to dye blue in any context. Even if the ancients did make murex indigo, why would people have used it to counterfeit techeilet when they could achieve the same results more cheaply with readily available plant indigo? However, there is an even stronger answer. Since murex indigo is equivalent to plant indigo, it would also fail the Gemara’s tests, so there was no need for a special warning. However, the Gemara’s need to warn us of other counterfeit dyes does pose a problem for P’til. The process used by Ptil will produce indigo from any of the purple giving mollusks. If murex trunculus indigo was true techeilet, why doesn’t the Gemara warn us of the perfect imitations that could be produced by related species?

Dye is superior if extracted from a live chilazon

The Gemara speaks explicitly about the case where a live chilazon is squeezed or crushed to get the dye out, and the person tries not to kill the chilazon in the process because the dye is better, or clearer, if taken while the chilazon is still alive.¹⁵ How long does it take to extract the dye from the chilazon? Seconds? Minutes? Yet, if the chilazon dies during this short process, the dye will not be as effective. Dr. Sterman’s argument that murex dye loses its power over several hours hardly satisfies this condition. This time frame ignores the fact that the Gemara speaks of the chilazon dying during the extraction process, a matter of minutes, not hours. Even more troubling is Dr. Sterman’s misrepresentation of Pliny and Aristotle. In my article I correctly state, as Rabbi Herzog also does, that Pliny and Aristotle warn that the dye should be extracted from the murex while it is alive because it discharges its dye when it dies.¹⁶ Dr. Sterman cites the first half of their statements, but then ignores the reason they explicitly state and instead supplies his own reason. In fact, these classical sources do not say anything about the dyeing power of the murex diminishing after death, their reason being at odds with the Gemara’s explanation regarding the chilazon.

Ancient blue dyes

Dr. Irving Ziderman states that it would be absurd to think the ancients would use murex indigo when they could make the same dye cheaper and easier by using plant indigo.¹⁷ Dr. Sterman responds with a series of unsupported statements claiming that Egyptians used murex for blue dyeing but not indigo, that murex dyeing in the Mediterranean dates back to the days of Avraham Avinu whereas indigo reached the region only 1,500 years later. There is a good reason Dr. Sterman fails to provide references for these statements – they aren’t true. There is absolutely no record of murex being used to dye blue in ancient times. All of the archeological evidence cited in P’til writings merely demonstrate it was used for purple dyeing, as is well known. In the classic work, The Art of Dyeing, by Franco Brunello, we find four sources of blue dye in ancient Egypt – none of them are murex.¹⁸ On the other hand, Brunello and others cite sources that conclude that indigo was used in Egypt over 1,000 years before Yosef’s arrival there, long before shellfish dyes were ever used.¹⁹ As for Dr. Sterman’s claims, they might be based on the work of late 19^th /early 20^th century Austrian Egyptologist, Alexander Dedekind, of whom P’til speaks highly. Dr. Dedekind’s claims about Egyptian use of shellfish dyes has been completely refuted and even ridiculed at length.²⁰ Dr. Gillian Vogelsang-Eastwood is probably the world’s leading expert on Egyptian textiles and has analyzed ancient Egyptian clothing from many eras, including those found in the tomb of King Tutenkhamun. In a personal communication she confirmed that the only blue dye she has found on Egyptian clothing is indigotin (from the indigo or woad plant), and that she has not found any evidence of purple shellfish dye in Egypt until the Roman era, about 1,000 years after the exodus from Egypt. There has been evidence of rare use of purple dye in Pharaonic Egypt, but this was found to be a mixture of indigo(blue) and alizarin(red).²¹

Techeilet, purpura and the color of purpura

Dr. Sterman brings an assortment of different sources that purportedly equate techeilet with purpura. Some of these statements make no mention of purpura, such as the statement he cites from the Radzyner Rebbe. The Ramban’s statement that even in his time only the King was allowed to wear techeilet hardly equates techeilet with purpura.²² In fact, during the Ramban’s lifetime (Middle Ages), there were efforts in several countries to restrict the use of blue to royalty and the very wealthy much like murex dyes during some periods of the Roman empire.²³ One must also be careful when dealing with the word techeilet since it may at times indicate a color with no specific origin. This is clear from the cited Ramban, since there was no kosher techeilet in the Ramban’s lifetime, yet he used the word techeilet to discuss contemporary blue dye. Other statements cited by Dr. Sterman are merely examples of purpura being used to connote Royal attire, as is commonly found in the Midrashim, and is used to refer to Mordechai’s royal clothing of techeilet, where the color of techeilet is implied, but not necessarily chilazon origin.²⁴ This is the simple explanation of Dr. Sterman’s quotes from the Aruch and Midrash HaGadol. Since the Midrash Hagadol, like Rambam, says that the color of the blood of the chilazon is “black like ink”, it would not make sense to suggest that it supports the notion that a murex snail is the chilazon.²⁵ Dr. Sterman cites the Makor Chaim (by the author of the Chavot Yair) and the Shiltei HaGiborim as explicitly stating that the purpura is the chilazon shel techeilet.²⁶ There are several problems with this. Both of these seforim are from kitvei yad that were discovered hundreds of years after they were supposedly written. Aside from possible issues concerning authenticity, and the more likely problem of the integrity of every word, in both cases the statements about purpura appear in isolation, i.e. there is no discussion of chilazon and techeilet, just a single statement. Both of these sources, especially the Baal Chavot Yair (“dam chilazon is not blue, but purple”), seem to be of the opinion that techeilet is purple, hence their conclusion as to the origin. Unfortunately, there is no discussion of how this species fits Chazal, or how the color of the blood contradicts the writings of Rashi and Rambam. Could there be errors in transcription? The Baal Chavot Yair seems clear, but the Shiltei HaGiborim would read quite naturally with argaman instead of techeilet. Seeing as how the notion of argaman coming from a mollusk was not well known, could an editor or copyist have inserted the word techeilet after seeing the word chilazon used in conjunction with dyeing?²⁷ In light of the fact that at the times they would have been written it was not known that blue dye could be made from murex snails, the simplest explanation is that they held the position that techeilet is purple and then made the natural corollary that the source was the famous purple-fish. Unfortunately, there is no evidence that either sage ever pursued their hypothesis in treatise or practice.

In my article I refuted efforts by P’til to demonstrate that murex snails were used to dye blue in antiquity. Dr. Sterman has not responded to my refutations, but instead offers another possibility. Vitruvius writes that depending on the location, murex purple could come out one of four different shades: black, red, blue and violet.²⁸ From the context it is clear that he is speaking of shades of purple, and is not suggesting that murex was used to dye blue or black. This is consistent with modern writings citing this work, as well as with Rabbi Herzog’s understanding of Vitruvius’ remarks.²⁹ Rabbi Herzog also demonstrates that Vitruvius was not speaking about murex trunculus, but of other murex snails.³⁰ Additionally, according to Vitruvius, the shade of purple associated with Tyre and Israel is red, not blue.

Dr. Sterman’s new set of criteria

Dr. Sterman proposes a new set of criteria. As stated earlier, Dr. Sterman says that Rabbi Herzog and the Radzyner Rebbe form the basis of any halachic discussion of techeilet. Their writings, as well as virtually all prior P’til writings, were based largely on the sugya in Menachot and other Talmudic sources. Dr. Sterman now dismisses those sources as aggadata and offers his own set of four criteria (the fifth “criterion” merely states that techeilet is not hidden and can still be found). As we will see, they not only form a peculiarly small and arbitrary set of criteria, but two of these criteria are not even valid.

“Techeilet is the color of k’la ilan”: Dr. Sterman seems to be unaware that there is no single shade of color produced from indigo. Indigo was used in ancient times to produce a wide range of blues, from light to dark blue. The fact that indigo can imitate techeilet does not tell us the color of techeilet. It merely tells us that one of the many colors produced by indigo is that of techeilet.

“Techeilet is a fast dye that does not fade”: Dr. Sterman’s quotation from the Rambam is appropriate and merely states that the dye is fast. The Radzyner Rebbe discusses this issue and understands it to mean that the mere passage of time in and of itself will not cause the dye to fade, though certain chemicals or repeated prolonged exposure to the sun could cause the dye to fade.³¹

“Techeilet dyes on wool, but does not take to other fabrics”: Dr. Sterman’s sources do not support this statement. The Gemara deduces from p’sukim about the garments of the Kohen Gadol that techeilet must be wool, but does not say or imply that techeilet dye cannot dye other fabrics.³² That techeilet can dye linen is clear from the Ibn Ezra who states that techeilet can be wool or linen.³³ Why Dr. Sterman proposes this criterion is especially surprising since indigo can dye linen, so murex indigo should also be able to dye linen.

“The dye from the chilazon is more potent if taken from a freshly killed chilazon, but one must kill the animal in order to extract the dye…”: This is puzzling. The Gemara states that the dye is better if extracted from the chilazon while it is still alive, as discussed earlier. The chilazon may die from being crushed, but the desire is to extract the dye while it is alive. As demonstrated earlier, murex trunculus fails to meet this criterion. Since the classical commentaries do not explicitly state that this sugya is speaking of the chilazon shel techeilet, and this property of the chilazon was not brought for the purpose of description, it is not clear why Dr. Sterman gives such prominence to this criterion over other references in Shas where the purpose is to describe the chilazon shel techeilet.

Objections to the Radzyner Rebbe’s position

Dr. Sterman cites two obscure seforim in raising three objections to the Radzyner Rebbe’s techeilet. Since neither my article nor his response treated the issue of the Radzyner’s position it is not clear why he chose to include these points, but since he took the liberty of raising these objections, I will take the liberty of rejecting them.

“Radzyner techeilet is not the color of the sky”: Prussian Blue, the pigment formed by Radzyner techeilet, can be either royal blue or sky blue depending on the proportions of the ingredients.³⁴ Further, it is hardly obvious what the color of techeilet should be. It is likened to the color of the sea, the sky and the sapphire. Dr. Sterman himself states that the term “domeh” only indicates a similarity in property. Indeed the Ibn Ezra says the color of techeilet slightly resembles the sky.³⁵ It is interesting to note that in artist pigments, indigo can be so similar to Prussian Blue, that a chemical test is required to distinguish the two.³⁶

“It fades when washed with soap”: While this sounds at first like a strong criticism of Radzyner techeilet, this appears to be a known characteristic of true techeilet! As cited by Rabbi Herzog, Rabbeinu Gershom states explicitly that techeilet fades in the wash.³⁷ The Radzyner Rebbe also quotes the Tosafot who state that techeilet fades in soap, and that k’la ilan does not.³⁸

“The dye can be obtained from dead sepia officinalis (and not exclusively from live organisms)”: This is confusing. First Dr. Sterman cites the Gemara as stating that the dye is better, or clearer, when taken from a live chilazon.

Then, in his new set of criteria, he says that it must be taken from a freshly killed chilazon, implying that it is taken from a dead chilazon and not a live one. Now, he says that it is impossible to get dye from a dead chilazon. The Gemara merely states that the dye is superior if taken while the chilazon is alive. The fact that it is possible to extract cuttlefish ink from sepia officinalis after it is dead is irrelevant. The issue is how effective it is in dyeing when it is extracted after death. The Radzyner Rebbe explains that when the cuttlefish ejects its ink it ejects the best of the dye and leaves behind the undesirable parts.³⁹ Italian chemist Dr. Rodolfo Nicolaus is one of the pioneers of sepiomelanin (cuttlefish ink) research, and in addition to the vast amounts of information on his web site, he was kind enough to provide scientific explanations of the Rebbe’s answer in a personal communication.⁴⁰ When cuttlefish ink is ejected it has more mature melanosomes, and is the purest representation of natural sepiomelanin.

When the ink is extracted from the sac, it is likely to be in contact with other components that cause transformations and degradation of the melanin. When the cuttlefish dies, this transformation takes place and the resultant ink is chemically very different from natural sepiomelanin.

Conclusion

Murex trunculus meets virtually none of the known characteristics of the chilazon. There is no evidence that murex trunculus was ever used to dye blue until recent times. P’til writings have suggested that people wear murex indigo based on the principle of sofeik d’oraita l’chumra. Given the overwhelming evidence against murex trunculus, there appears to be little sofeik.

Addendum (not published)

Tosafot (Shabbat 75a) suggest that the reason a person is not chayiv for trapping a chilazon on Shabbat is because when it is caught it jumps about, thereby hastening its death. As Rabbi Mordechai Kornfeld, Rosh Kollel of Kollel Iyun HaDaf, points out, a snail does not fit this criterion of Tosafot (see http://www.shemayisrael.co.il/dafyomi2/shabbos/insites/sh-dt-075.htm).

Above, it was argued that it is meaningless to claim the color of techeilet is the color of indigo since indigo can be used to make a vast spectrum of blues depending on the dipping technique. This is supported by Tosafot (Chulin 47b) where it is stated that indigo, which resembles the sky, only slightly resembles (domeh k’tzat) techeilet, and that one can distinguish between indigo and techeilet some time before sunrise. This suggests that the true color of techeilet is not the shade of blue most commonly associated with indigo, though indigo can be made to imitate techeilet.

Footnotes

1. Rabbi Gershon Leiner, Eyn HaTecheilet, published in Sifrei HaTecheilet Radzyn (Bnei Brak, 1999), p.387. ↩
2. Hilchot Tzitzit 2:2. ↩
3. Masechtot Ketanot Masechet Tzitzit Ch. 1 Halacha 10. ↩
4. Herzog ibid., p. 73. ↩
5. David H. Tompsett, Sepia (Liverpool, 1939), p. 143, citing the work of Grimpe; Transactions of the Royal Society of Edinburgh, Vol. 61, Part I, 1943-1944. (No. 9), pp. 247-260. ↩
6. Rabbi Isaac Herzog, “Hebrew Porphyrology”, in Ehud Spanier, ed., The Royal Purple and the Biblical Blue: Argaman and Tekhelet (Jerusalem, 1987), p. 70. ↩
7. www.chilazon.com ↩
8. Rambam Hilchot Tzitzit 2:2; Midrash HaGadol Shemot 25:4; Philo, De Congressu, as cited by Herzog, ibid., p.87; Rashi Chulin 89a. ↩
9. Avodah Zarah 28b; Celsus ibid. Book 2:30. ↩
10. Leiner, ibid., Sefunei Temunei Chol,,p. 27;Keilim 12:1 and Tiferet Yisroel ad loc. ↩
11. Flavius Josephus, Antiquities of the Jews, Book 3 Chapter 7. ↩
12. Leiner, ibid., pp. 14-17. ↩
13. Herzog, ibid., p. 65. ↩
14. Herzog, ibid., p. 70. ↩
15. Shabbat 75a and Rashi ad loc. ↩
16. Herzog ibid., pp. 74-75; Aristotle, Historia Animalium, Book V, Ch. 15; Pliny the Elder, Naturalis Historia, Book 9, Ch. 60. For a picture of a murex snail discharging its dye upon death, see Nira Karmon, “The Purple Dye Industry in Antiquity” (hebrew), in Chagit Sorek and Etan Ayalon, eds., Colors from Nature: Natural Colors in Ancient Times (Tel Aviv, 1993), p. 85. ↩
17. I.I. Ziderman, “On the Identification of the Jewish Tekhelet Dye”, Gloria Manis [Antwerp] 24(4): 77-80. ↩
18. Franco Brunello, The Art of Dyeing in the History of Mankind, translated by Bernard Hickey (Venice, 1973), p. 43. ↩
19. Brunello ibid p.43; Helmut Schweppe, “Indigo and Woad”, in Elisabeth West FitzHugh, ed., Artists’ Pigments: A Handbook of Their History and Characteristics, vol. 3 New York, 1986), p.83. ↩
20. Meyer Reinhold, History of Purple as a Status Symbol in Antiquity, (Bruxelles, 1970), pp. 13-14. ↩
21. Gillian Vogelsang-Eastwood, “Textiles”, in Paul T. Nicholson and Ian Shaw, eds., Ancient Egyptian Materials and Technology (Cambridge, 2000), p. 279. ↩
22. Ramban Shemot 28:2. ↩
23. Daniel V. Thompson, The Materials of Medieval Painting (New Haven, 1936), p. 127. ↩
24. Esther 8:15; Midrash Esther Rabbah 10:12; Chidushei Radal Bamidbar 13:18. ↩
25. Midrash HaGadol ibid. ↩
26. Makor Chaim 18:2; Sefer Shiltei HaGiborim ch. 79. ↩
27. Josephus ibid. ↩
28. Vitruvius, De Architectura, Book 7 Chapters 7-14. ↩
29. Thompson ibid., p. 156-158; Herzog ibid., p. 26. ↩
30. Herzog ibid., p. 34. ↩
31. Leiner ibid., Sefunei Temunei Chol, p. 10, written before he produced his first batch of techeilet. ↩
32. Yevamot 4b. ↩
33. Ibn Ezra, HaPeirush HaKotzeir, Shemot 25:4. ↩
34. J.N. Liles, The Art and Craft of Natural Dyeing, (Knoxville, 1990),p. 49. ↩
35. Ibn Ezra ibid. ↩
36. Schweppe, ibid., p. 94. ↩
37. Rabbeinu Gershom, Menachot 43a. ↩
38. Leiner ibid., P’til Techeilet p. 82; Baba Kama 93b; Tosafot Zevachim 95a; Nidah 62a. ↩
39. Leiner ibid., P’til Techeilet p. 54. ↩
40. www.tightrope.it/nicolaus ↩