Posted by Steve Price on June 24, 1999 at 08:25:09:
In Reply to: Other Alternatives on dating rugs posted by Erol Abit on June 24, 1999 at 04:31:29:
Dear Erol,
Your proposal is interesting, although (as you say) it would take a lot of work to bring it to a useful state.
Perhaps this would be a good time to mention some other physical methods (besides C-14 analysis) that have surfaced from time to time.
I know of two that seem promising, neither of which seems to have developed very far.
1. Amino acid racemization: Proteins, which is what wool is, are large molecules made up of chains of amino acids. Each amino acid can exist in two forms, mirror images like your right and left hands. Animals only use one of the two forms to make proteins. Thus, newly made wool only has "L" (as in, "left hand") amino acids. Over time, amino acids more or less spontaneously revert to the right and left handed mixture. This process is called racemization (you don't want to know why, trust me). In principle, the extent to which this has occurred in wool could be a measure of how long it is since the sheep made it.
2. Amino acid oxidation: One amino acid, called cysteine, spontaneously oxidizes to form a different one, called cystine (note the subtle spelling difference; we needn't discuss its absurd consequence on pronunciation). If you know the ratio of cysteine to cystine in new wool, in principle you can measure that ratio in an old rug and determine how long ago the wool in it was part of a sheep.
It would be wonderful to have either or both of these methods brought to a useful state. Neither is likely to be something a rug collector can carry around in his pocket, but then again, neither is C-14 counting equipment.
If any of our readers know of other physical methods that have potential use in rug dating, I invite you to post them.
Steve Price