Lashley, Europe, Dental Plaque discussed on Science Magazine Podcast
When you go to the dentist. There is pleasant process where they scrape your teeth, and they take is called dental calculus or tartar off your teeth is that lesson for any. No. But luckily that is a relatively new thing and back in the day. And like medieval times, people were not having their teeth scraped every three to six months, and I say lucky because there's precious information hidden in that dental calculus may be able to learn about the oral microbiomes of the people who live in the past and also about different diseases that they might have had. And now, it's also telling us things about their occupations what they did every day or or kinds of chemicals encountered in their lives. I have Christina Warner here. She's gonna talk about some dental calculus that was contaminated with a blue mineral, so Christina. What did you find these blue particles associated with dental calculus on these remains was when we first saw them? I mean, probably the last thing I would have expected to find we were trying to look at it in house. Yeah. We expected the bacteria has after all calculus is made a plaque dental plaque. Which is made up of bacteria, and we expected to find little bits of food because when you're alive, and you have plaque on your teeth, and you're eating or your smoking or your breathing and pollen all these little things. Get stuck in your plaque overtime, the plaque calcified at mineralized in your mouth from the minerals in your saliva. In fact, it's the only part of your body that fossilising while you're still alive, and this actually happens over and over again these layers actually build up almost like tree rings or layers of an onion. So after you've calcified one layer you'll form another layer that apply can keep doing it. This woman that we looked out. We actually cross section debt, and there were so many layers. It really looked like this calculus hadn't been removed in twenty or twenty five years that had so many layers built on top of each other. But for an archaeologist this is a gold mine. It's like a time capsule that tells the story of of this woman's life. What was the first thought from the group if you know, they saw these little blue flecks in in her teeth under the microscope? We had no idea what it was. We could be some sort of contaminant is there's something in soil. That's blue. Yeah. No, no. There's not we looked into extensively actually blue minerals are very rare. They tend to be things you have to mind from deep in the earth. They don't occur in surface sediments. So we thought well, maybe maybe it's a it's a mineral of some kind, and maybe it's a paint. Because certain was so blue was Royal blue the brightest brightest blew it looked like Robin's eggs tiny little, Robin. I bet it. I was probably as right as right is a pretty common mineral, it's a pretty inexpensive mineral, and it's really widespread across Europe. And it was used by are in the middle ages. I was pretty sure it was as right? It ended up being fairly complicated to identify for a number of reasons. One is as we were looking at it the blue began to fade and disappear. Oh, yeah. This happened over and over again it took a while. I figure out what was happening, and we finally figured it out when you wanna look at calculus under a microscope. You can't just put under microscope. It's too compacted. And you have to break it up and the usual way of doing this is to apply a little bit of weak acid, and it just dissolves the mineral enough to allow the particles to come out. It turns out that many mineral pigments are actually unstable in the presence of acid and they lose their color. That's what we were seeing. So that gave you a clue that maybe it wasn't as right? We'll also breaks down from we actually tested many different reference, pigments and determine which were stable in. Which were not. So like cobalt blues is stable. But as right is not and Lashley was not there, aren't that many lose that were available to the medieval painter, they had a admitted access of the blues that they had available to most blue because of particular element. So cobalt blue is split because cobalt, Azure is blue because of copper, Vivian. I is blue because iron Rapids Lashley, actually, not one mineral. It's a bunch of minerals together. Blue component is called laterite. There's also white minerals in they're called slug apply and also pyrite the golden flex that. People often recognize one thing your paper reminded me of is that in a television show, and they say what is this mineral residue and just handed to the lab and that have hands and back and answer is never that easy. You had to go through a lot of steps to identify. What exactly was going on here on these T? So what were some of the tests that you had to subject this mineral to will the trouble with Lazarie? The blue mineral is that there's nothing unusual. About it. In terms of its elements made up of the same elements that are found in soil just configured very differently into in their mineral structure, and so we use a technique called Rahman spectroscopy which actually allows us to look more at the mineral structure itself, and that we were able to get a very good match for lodge right after we identified the blue crystals as being a match using two different methods for laterite. We thought let's test some of these white particles that ordinarily would completely ignore and they turn out to flog apply laterite and flog pie only Coker together in legislation that gave you that confidence that you what you are looking at. But it's really surprising that that's what you're looking at. It was extremely surprising. This Lashley was one of the most expensive and rarest artists materials of the middle ages. We did not expect to find it. I think it's hard for us understand how expensive it was. And how difficult it would have been to get their lap. Lashley only had one source during the middle ages, and that WAS FG. Anniston? So this pigment had to traveled from its source in Afghanistan overland along the paths of the silk road, basically at through the Islamic world. Whereas probably refined into a pigment traded up into Venice. And then distributed into Europe made in extraordinary six thousand kilometer journey to make it into the mouth of this very ordinary one about that in women. What about that last little bit of the journey? How would it end up in her mouth? I mean, there's no way this could happen completely Occidental's. She must have been exposed in a very intimate way. But help Osprey happen. Now, we spent a long time debating what the possible scenarios could be. I have my favorite. It's not the one that it is my favorite is all the the book kissing that people were doing it. The look if think has so so this is really incredible during the middle ages, but but actually later than the that was eliminated it. Yeah. Yeah. During the fourteenth century, there's this sort of fat. Bad for what they call emotive devotional osculation so says like intense kissing books, and the idea was to become very affectionate with the images. Eventually they started creating these little osculation targets at the bottoms of the pages to try to encourage priests, for example to kiss the target and not the face of Jesus because it was wiping away face that one was discarded because it was it wasn't the timing wasn't right. And let's turn to one of the what are the likely scenarios in which woman would have introduced us into her mouth. So he came up with two of the we thought were more likely that either she was trying to produce a pigment herself. And thus may have inhaled some of the dust, and that was so she would probably producing it either for herself or one of her sisters or she was an artist herself with the first scenario, although it's possible. I don't think it's likely for one reason. And that is because if you just take lapis largely Sony new grind now you'll. Will get a really dull gray pigment. It's not nice. It has too much of the flog pie and other minerals inside that dole the color. So what you have to do is you have to refine it and the technique use to refine lavishly at this time wasn't really known in Europe. It was primarily performed in in the Islamic world. But what I think is probably the most likely is that she was an artist herself, we do know from some artists manuals around the same time that one technique for producing a really fine point for for fine painting work involved. Compressing the the paintbrush between the lips the lap is largely was quite distributed through her mouth zone. It wasn't Dustin one place. It was also really disperse. So it didn't seem to have been incorporated as a paint, for example, if she had kissed it had gotten stuck an also there are some really amazing letters from right around the same time period. Maybe a little bit later. Also in Germany where there is a men's monastery. There's an or Mario. Who is the keeper of the books and he had commissioned the production of several new books from a neighboring women's community. So when you say when you say she was an artist it's more about eliminating manuscripts than it is about making paintings, correct? It was very likely for eliminating manuscripts. Because it was a lot of book production right at this time. It gives evidence that women were producing books and they were producing important books. Yeah. But unfortunately, these letters don't stay which pigments were being used we can tell by the amount of silk, and the amount of parchment that he was sending for these books to be made that they would have been quite nice books. Is there anything else from the grave site or from the ruins of the monastery where where this this remains were or anything else there that would help with that the women's community from the letter was different one. Okay. Not this community. The remains of from a site called doll. Heim doll Heim is located in western Germany and today. It's actually the site of museum about monasteries and the cemetery that we focused on was one of the very associate with one of the earliest religious communities that was founded in this area, and it was a women's community with interesting about all Heim is almost nothing survives at all. Today. You can go and visit and I recommend doing. So it's really fun. But all that's left of the women's community is the stone Dacians, none of the walls. Are there? There's no art that survives. There's not a single book that survives this poor women's community, which at its at its height supported actually, very small group of women. Only about a dozen women live there at any given time it underwent multiple fires burned to the ground multiple times. It was sacked in at least to battle. It was hit by plague and eventually it was abandoned during another war and a non was murdered and the whole community fell apart this was centuries later, and then later a group of monks moved in and they built a monastery, and that's the monastery. That actually release revives there today. And that today is really the museum people go to visit. But you can still find this kind of traces of this little women's what they call a frown closer this little women's monastery, a little women's community still bear the church foundations and the foundations of of the place where they lived, but it's very small kind of tucked away and forgotten. It's like had just been a rate how absolutely race. And so to me that was something that was so interesting is in this totally unexpected context from this very ordinary seeming woman from the cemetery we've been able to identify someone who was likely in live, quite extraordinary person. She must have been a very talented artists, and I say artists here because lapis Lashley was not used by scribes who is not used typically to write words, it was used to illuminate pictures. Wow. That is amazing. So other other remains from the site that that might be able to shed more. Light on this. We only in this. Initial study looked at for individuals. And that was because we had a completely different purpose to the study originally. I think what this has shown me is that this could be a really important way of going back and revisiting many monasteries and identifying artists and crafts people one of the big lessons. We learned here is it's also very important. How you analyse the calculus in most cases, what people would normally do is start the decalcification with the acid walk away. Wait till it was finished. Come back all of it would have been gone. So it made me wonder how many artists have already been looked at. But because of the way the calculus was treated, we never saw it. Yeah. So one of the things we want to go back to ply these new techniques and to see if we could kind of approach is in a different way is start to identify the artists themselves in the archaeological record how common was it for women during his time to be scribes or to be. Arneses involved in bookmaking as a fantastic question. And this is something that Alison beach who's the historian of the project has researched extensively and she's turned up quite a bit of evidence of women who were prolific producers of books, but a lot of detective work has had to go into this because one of the tones we face as women often did not sign their works in some cases, a list survives on non later. None for example, would write down that sister. So and so wrote these books, but if you look at the books themselves, nothing indicates that what she was also able to do is take one book that was signed and match the handwriting to several other anonymous books, and so we could see okay. This group was all written by one person. And here it signs. We can apply that name to all of them. But it's really painstaking work to try to reconstruct this. And so I think it's really helpful to have the second line of evidence. Any many people might think that archaeologists and historians worked together because we were. On kind of similar things. But actually, it doesn't happen that often we kind of exist in different worlds, one group lives in libraries and one group dig in the dirt, those are very different. So you guys are not all Indiana Jones, your son. No, we're we're quite different. You know, here was a really great problem that we all got to sit together and really talk about. And then we needed more. So we teamed up with physicists. So it was a fun project where we really had archaeologists historians physicists all sitting together. Talking trying to puzzle out this question, and that was tremendous fun. That is really cool really seems like this is a totally different way of doing archaeology. Who would have thought that? If you wanted to understand artists in the middle ages. You would look at their dental plaque. Yeah. Sometimes I think we get tripped up with thinking that artifacts are only stone tools and pottery, but there is this entire archaeology of the invisible that is out there that we are only now starting to appreciate things decompose breakdown at a at a large scale. But. Any of the microscopic particles and the bio-molecules actually preserve were really really longtime. How I feel like we're right now in the renaissance of archaeology like with a lot of new scientific technologies that are available were kind of new kind of archaeology as being born. And I'm really excited about it. Very cool. Okay. Thank you again casinos than really fun. Thanks so much. Cristina Warner is a professor in the department of arguing genetics at the Max Planck institute for the science of human history. You can find a link to her research insights Vance's at science MAG dot org slash podcast. And that concludes this edition of the science podcast, if you have any comments or suggestions for the show right to us at science podcast at a s dot ORG. You can subscribe the show anywhere. You get your podcast or you can listen on the science website. That's science MAG dot org slash podcast to place. An on the science podcast contact mid roll dot com. The show is produced by Sarah Crespi and Meghan can't well and edited by podgy Jeffrey cooked composed the music on behalf of science magazine and its publisher AAA offs. Thanks for joining us.