2007年10月23日

放射性炭素年代測定法がアッシジの聖フランチェスコの礼服の年代に疑問を投げかける

いつもお邪魔しているMegurigami Nikkiさんの記事を拝見して、大変興味深いニュースを知ったので私も探してみました。

robe_relics.jpg

Carbon dating casts doubt on age of St Francis robe
【REUTERS UKより、以下転載】
ROME (Reuters) - Carbon dating has cast doubt on the authenticity of one of four robes kept by Italian churches as relics of the medieval Saint Francis of Assisi, though another tunic, a belt and a cushion were found to be the right vintage.

Friars from two churches of the Franciscan order founded by the saint asked a laboratory specialising in dating artwork to examine two simple brown tunics said to have been worn by the champion of the poor, as well as a mortuary cushion.

Francis who gave up the life of a playboy and soldier and all his worldly goods to dedicate himself to the poor and preach the way of peace, died in 1226. His hometown, Assisi, attracts millions of Christian pilgrims every year.

Artistic depictions of the saint show him dressed in a brown robe with a rope belt -- the habit still worn by his order.

Four Franciscan churches have claimed to house relics. The tests showed that one, in the Basilica of Cortona in Tuscany, did date from his lifetime, as did an embroidered cushion said to have come from his deathbed.

A second robe from Florence's Basilica of the Holy Cross did not match the dates, though the belt around it did.

"The tunic and cushion from Cortona were found compatible with the period in which Saint Francis lived but the one from Florence wasn't," said Pier Andrea Mando of the Nuclear Physics Laboratory in Florence, in a statement released on Wednesday.

The other two robes are kept in churches in Assisi and Arezzo belonging to a different branch of the order and were not included in the tests, which used accelerator mass spectrometry to measure the amount of carbon-14 present in samples of cloth.

Francis, the son of a wealthy merchant, is said to have found his vocation while praying in a ruined wayside chapel. He heard a voice saying: "Go, Francis, and repair my house."

Pope Benedict visited Assisi in June for the 800th anniversary of St Francis' conversion.

Carbon dating of St Francis' robes has none of the controversy surrounding tests in 1988 on the Shroud of Turin, which bears an imprint many Catholics believe to be Jesus and has been venerated for centuries as Christ's burial cloth.

Findings dating it from at least 1260 AD were bitterly contested by some in the Church.
鑑定した四つのうち、一つが聖フランチェスコの生きていた年代と一致しないということらしいのです。

逆にいろいろな聖遺物関係の本を読んでいると、あれほど偽物が横行する聖遺物にあって、この確率で本物だったならば、かえって凄いと思うのですが、みんなそんなふうに考えないんでしょうね。

これらの聖遺物を所持する当事者の教会は、相当大変なことになるのでは・・・などと他人事ながら、余計な心配をしないでいられません。

でも、聖骸布といい、ジャンヌ・ダルクの骨といい、興味深い時代になったものです。

他にも、同様の内容で次のような記事がありました。

robe_relics1.jpg

Physics Reveals The Secrets Of Saint Francis
【ScienceDailyより、以下転載】
The tunic believed to have been worn by Saint Francis of Assisi preserved in the Church of Saint Francis in Cortona (Province of Arezzo) dates back to the period in which the saint lived, whereas the tunic preserved in the Church of Santa Croce in Florence was made after his death.

Carbon 14 measurements, which allow a relic to be dated, show that the tunic in Santa Croce dates back to some time between the late 13th century and late 14th century and thus could not have belonged to the “Poor Man of Assisi”, who died in 1226. These and other discovers were made possible through the analysis of the relics with a tandem particle accelerator, which was performed by the Laboratory of Nuclear Techniques for Cultural Heritage (LABEC) of the INFN of Florence.

The results of the study were presented in Florence at the European Conference on Accelerators in Applied Research and Technology (ECAART) and will be published in the volume “L’eredità del Padre: le reliquie di San Francesco a Cortona” (which will be released in a few weeks by Edizioni Messaggero di Sant’Antonio). The volume will include the complete results of an interdisciplinary investigation which included both scientific and humanist research and which was promoted by the Tuscany Province Chapter of the Franciscan Order “Friars Minor Conventual”.

The analyses were conducted with a radiocarbon method, measuring the radiocarbon using Accelerator Mass Spectrometry (AMS). From each tunic, researchers took from 5 to 7 samples of fabric, each of which was smaller than one square centimetre and weighed around 10 milligrams. Multiple samples were taken to avoid doubts or ambiguities (due to, for example, the presence of patches that were added to the tunic at a later time), thus increasing the analysis’ validity.

Each sample of wool was then treated so as to extract only the carbon, obtaining a small graphite pellet weighing about 0.8 milligrams. The pellet was then placed in the accelerator’s chamber, where it was exposed to a beam of cesium ions, “scratching” the pellet’s surface and extracting carbon isotopes 12, 13, and 14. The accelerator used by the INFN separately measured the quantity of the three isotopes. Relics are dated by calculating the ratio of carbon 14 to carbon 12, the quantities of which are “counted” in the accelerator’s detectors. Both great delicacy and exceptional sensitivity are required for taking these measurements; in fact, the ratio of carbon 14 to carbon 12 is only around one to one trillion, or even lower.

The analysis of the tunic preserved in the Basilica of Santa Croce in Florence showed that it dates back to a period between the end of the 1200s and the end of the 1300s, revealing that it was made at least 80 years after Saint Francis’ death and thus could not have belonged to him.

By contrast, the dates of all of the fragments taken from the tunic in the church in Cortona coincide with the period of Saint Francis’ life (the average results show that the tunic was made between 1155 and 1225). The tunic is one of three Franciscan relics, which also include a finely embroidered cushion and a book of gospels believed to have been brought to Cortona by Friar Elia, Saint Francis’ first successor as leader of the order.

LABEC researchers also analysed the composition of the precious metal thread used to embroider the cover of the cushion on which the Saint’s head was placed upon his death, and they used the carbon 14 method to date the fabric of the cushion itself. Moreover, the book of gospels was subjected to in-depth codicological and paleographic investigations by researchers at the University of Siena. Based on both the scientific evidence and humanistic research, the cushion and the book of gospels were also found to date back to the period in which Saint Francis lived.
こちらの方が、テスト方法など詳しいですね。調査結果は、“L’eredità del Padre: le reliquie di San Francesco a Cortona”という名称で出版されるようです。英語じゃないんだ、読めない・・・残念です。

関連ブログ
ジャンヌ・ダルクの遺骨は偽物で、エジプトのミイラ=研究者が発表
『トリノの聖骸布』の印影は復活の時のものか
「トリノの聖骸布―最後の奇蹟」イアン・ウィルソン 文芸春秋
「聖遺物の世界」青山 吉信 山川出版社
posted by alice-room at 21:35| 埼玉 ☁| Comment(2) | TrackBack(1) | 【ニュース記事A】 | 更新情報をチェックする
この記事へのコメント
記事中の調査結果は、イタリア語のものですね。読めないことはないのですが、時間かかりそう・・・。さすがに本家のアッシジは、そういう調査に挑むリスクは踏まないかと思いますが。
Posted by Nikki at 2007年10月24日 23:54
Nikkiさん、こんばんは。イタリア語・・・以前、イタリア語講座に通っていたのに3ヶ月持たず挫折してしまった私としては、読めそうにありません(涙)。

フランス語なら、改めて勉強したいなあ~と思ってはいるのですが・・・それも怪しい?

アッシジは確かにおっしゃるように万が一、ってこともありますし、リスクは冒せないでしょうね。同感です!

しかし、本当に興味深いお話です(笑顔)。
Posted by alice-room at 2007年10月25日 20:39
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アッシジの聖フランチェスコの修道服は本物か?!
Excerpt: sabato, 8 settembre 2007 sono l'uno e trentatre 【ニュース情報】 ■Title:Saint's robes carbon dated&..
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Tracked: 2007-10-24 23:56