The piece of linen called the shroud of Turin, which has been the subject of considerable dispute for six centuries, will soon be subjected to full-fledged scientific tests for the first time.
And in keeping with the history of the relic, verbal battles have started over procedures to be used in examining the cloth. The difficulty has less to do with the tests themselves than with the potential for fraud before the tests start.
Last fall, the Catholic Church, after years of entreaties, agreed to submit the cloth to carbon-14 dating. The linen, about the size of two dining-room tablecloths laid end to end, carries a faint straw-colored image of both the front and back of a man's body. It first surfaced in France in about 1350, the property of a knight who is said to have obtained it as loot from the crusades in Palestine.
The production of fake religious relics was common at the time, and the suggestion that it was the burial sheet of Jesus of Nazareth has been questioned ever since.
In 1981, a group of scientists subjected the cloth to photographic image enhancement and tests of tiny bits of fabric lifted from the cloth with sticky tape. Their conclusion was that the image was probably not painted, but was produced by some unknown process. The chief hypothesis among members of the group was that the image was made by oils from a man's skin that adhered to the surface of the cloth and discolored with time.
The new examination plans begin with cutting a small sample of the cloth, then dividing the sample into seven parts to be sent to laboratories in several different countries. Each laboratory will also receive dummy samples to test, without any indication of which is fake or real.
Dennis Dutton of the University of Canterbury in New Zealand wrote recently in the British journal Nature that those in charge of the testing -- the Pontifical Academy of Sciences and the British Museum -- have declined to divulge details of the testing procedure, citing "confidentiality."
"The situation as it now stands is most disturbing," he wrote. "Evidence for or against the authenticity of a relic of such widespread veneration involves deep religious passions: for some people there is a great deal potentially to be lost. So there must be no hint that, for example, fibers of mummy linen might have been supplied to the laboratories, rather than actual shroud samples. If those conducting the tests wish to be taken seriously, they must offer their procedures to open inspection by independent observers. . . . "
In the June 25 issue of Nature, Harry E. Gove of the University of Rochester, one of the laboratories to study the shroud, replied that "the removal of the shroud sample by a noted textile expert from the Abegg-Stiftung in Bern, Switzerland, will be witnessed by representatives of the seven carbon-dating laboratories."
The results of the work are scheduled to be announced at Easter next year.