Podcast Transcription

Steve Mirsky:       This Scientific American podcast is brought to you by Audible.com, your source for audiobooks and more.  Audible.com features 100,000 titles including science books like Mary Roach’s new book, Gulp: Adventures on the Alimentary Canal, and Thinking Fast and Slow, by Nobel laureate Daniel Kahneman.  Right now, Audible.com is offering a free audiobook and a one-month trial membership to the Scientific American audience.  For details, go to Audible.com/sciam.  Welcome to the Scientific American podcast Science Talk, posted on April 16, 2013.  I’m Steve Mirsky. 

Mary Roach:         A fistulated cow is a – you put your arm in and you feel, first of all, inside the rumen, it’s fermenting.  It’s a composter, it’s hot in there. 

Steve Mirsky:       And that is Mary Roach, author of Stiff, Spook, Bunk, Packing for Mars and now Gulp: Adventures on the Alimentary Canal.  Mary’s book tour took her from her west coast home to New York City, so we met up early on the morning of April 3rd at her hotel in midtown to chew the fat.  Be warned, some graphic language and subject matter is ahead.  Mary, you're chewing on tampons, you're sticking your arm into a cow, living cow’s stomach, you're not hooping but you're writing about it.  How – you’ve got the entire digestive tract, alimentary canal covered. 

Mary Roach:         The whole food chute, from pie hole to butthole. 

Steve Mirsky:       And how did the book germinate? 

Mary Roach:         I'll tell you how it germinated.  Well, there were some contributing factors other than this, but this was a story many moons ago, the assignment was flatulence, and I went to the Beano Corporation, where they have a research center, and I was a subject, and I – my editor at the time, and I shall not name names, but she didn’t have quite the same sense of fun that I do, and so the piece – I felt that I didn’t – wasn’t able to capture the true joys and surprises of flatulence research, and I got this sense that there was just so much more fun to be had on the alimentary canal than I had been able to have in this 1,000-word story. 

Steve Mirsky:       She kind-of took all the gas out of it. 

Mary Roach:         She let the air out, Steve [laughter]. 

Steve Mirsky:       And so that was the beginning and how did you decide that you wanted to just do, from A to Z

Mary Roach:         The whole nine yards, and it is around nine yards, although that’s not where that term comes from.  I don't know, it’s just right up my stinky little alley, isn't it?  [Laughter] Is it any surprise that I did this book, really? 

Steve Mirsky:       No, when you consider the last one, I remember when the space book came out, what was the title again? 

Mary Roach:         Packing for Mars

Steve Mirsky:       Packing for Mars, we had an extended discussion on the trials and tribulations of going to the bathroom in weightless conditions, so this, in some ways, a natural extension. 

Mary Roach:         It is, indeed.  I had a lot of fun with that chapter.  People who hadn’t read the book, who only hear the publicity, believed that I wrote an entire book about going to the bathroom in zero gravity.  It’s not true, ladies and gentlemen, one chapter, but that chapter drew a tremendous amount of attention, which also led me to think I’m not the only one with a 12-year-old sensibility when it comes to these things, and that it’s – setting aside childishness, I think it’s – everybody has these organs inside them, and let’s say hello.  Let's say howdy-do to our interior and –

Steve Mirsky:       Didn’t Aristophanes make fart jokes? 

Mary Roach:         I believe so, yes, he took it to perhaps a higher level than I've been able to do, but yes, getting right down to it, it’s a – it’s the whole business, even the mouth, not just the – I’m doing the whole – the nose, even the nose, the noble nose is in the mix.  So I just found – I found it interesting, and I’m kind-of a – I like to write about what I find interesting, so. 

Steve Mirsky:       So let's talk about why were you chewing on a tampon.  Well, take a sip of water first, to start the process. 

Mary Roach:         To start the –

Steve Mirsky:       What could be more appropriate, you just gulped some water. 

Mary Roach:         Some water.  I – why was I chewing on a tampon, well, it wasn’t just a tampon, it wasn’t a feminine hygiene device, it was the Salivart Collection System, and it’s collecting stimulated saliva, which is the kind of saliva that is produced when you chew on something, and your body – I – your body’s – you would think it would only happen when you chew on food, but your body’s kind-of like, “Well, who am I to say what she’s planning to swallow?”  Whatever you put in your mouth and chew on, your body’s going, “OK, I can moisten that for you, I can help you here, let me produce some saliva,” and in the case of a tampon, or the Salivart collecting wad, it’s a very challenging – it’s a challenging item for the saliva to – so it’s producing – you're producing a lot when you chew on something, your body’s producing saliva, this tampon, or il tampone in Italian, the directions were in four languages, so when you chew on il tampone – maybe that's the plural, I’m not sure – it collects it, it’s also absorbing it.  So then you can take it out, put it in a centrifuge, get the stimulated saliva out and then see how much you produced.  And so I was in the lab of Erika Silletti, who’s a beautiful Italian woman who’s devoted her – this portion of her career, anyway, to the study of saliva. 

Steve Mirsky:       She was so upset when she gave her first lecture on the subject and people didn’t take it all that seriously. 

Mary Roach:         No, she was – I think it was a dental conference and she said, “They think of it as moistening and that's all,” she was very offended, though.  And now that I've spent a day at her lab, I understand why she would be a little – not hurt, but chagrined that people were failing to appreciate the miraculous properties of saliva and all the many, many things it does, which I could get into here if you wanted me to, but. 

Steve Mirsky:       It’s natural when you find something fascinating to be a little hurt when other people don’t think it’s as interesting.  Give me three interesting things about saliva that all of us people who have it probably don’t know about it. 

Mary Roach:         It has anti – people think of it as this dangerously bacteria ridden – and there is a lot of bacteria in saliva, because any time you touch your food – put your food in your mouth or your finger or whatever, you're introducing bacteria into a warm, moist, tropical paradise for the bacteria, so yeah, there is.  But there – but your saliva has all these antibacterial elements, and studies have been done.  There was one where there was a rodent – a couple of rodents and one of them, the salivary mechanism was disconnected.  They – and they both had – they had wounds, and then the mouse that couldn’t lick its wounds, the wounds healed more slowly, there are wound – there's elements of saliva that help with wound closure and skin growth and so it’s a whole – there are old medical – you look back in medical texts from the 1600s and 1500s, and there’d be, “Apply the fasting saliva of a 70-year-old man to the shank,” or – and it will cure you [laughter]. 

Steve Mirsky:       So you’ve got to go find somebody else’s saliva, you can't use your own. 

Mary Roach:         Yeah, which made no sense, but I think it felt – it seemed more like a medicine if you – if it was – if it came from some other source.  But animals lick their wounds, and the whole business of kissing a baby’s boo-boo.  You're like, “Oh, let me kiss it for you,” there's a little bit of truth to that.  What else?  Saliva also – saliva is – this is an experiment that Erika Silletti did with me.  She took a medicine dropper that had some vinegar, put it on my tongue, she goes, “Do you feel it?  Do you feel it?  It’s coming in,” and it’s this rush of saliva when you put anything acid – like in the pH range one, two, three, anything that's vinegar, wine, orange juice, cola, and if you pay attention, which I had never done before, you do.  You feel this like, gush of body temperature liquid like, rushing into your mouth like the cavalry, just to dilute – to buffer the acid, so that you don’t dissolve your tooth enamel, which – and acid in that range is pretty effective at dissolving, softening your tooth enamel.  So and it happens like, poof, just instantly.  It’s – and for days, I was – I would have – if I had a Coke or something, I would take a sip, I’m like, “There it is, there's my saliva rushing in to save the day.”

Steve Mirsky:       Because the phosphoric acid in the Coke is so – the pH.

Mary Roach:         So low pH, so anything low pH.  It’s – and can – like those citrus candies, too, the same kind of – which people who don’t have a lot of saliva, that's partly why those are helpful, they – because the acid makes you generate saliva. 

Steve Mirsky:       When reading the book, I was – I remembered a friend’s mother has lost the ability to smell, and there's all kind – because so much of flavor, as you point out in the book, is smell rather than the taste that happens on the tongue, it’s really disruptive, because nothing has any kind of pleasurable aspect when you eat.  So these people who’ve lost the sense of smell tend to eat a lot of creamy food, which is really high calorie because it’s really fatty, and I remember an incident where my friend had given her mom a cookie, and her mother chewed the cookie and then said, “This is really good, how does it taste?”

Mary Roach:         [Laughter]  It’s – I have a friend, in fact I just saw her last night, who has almost no sense of smell, and I don't know if it was a medication related thing or – she says there's no – she claims she has no sense of smell.  We'll go out to dinners, like what are you going to get, this all looks good, she’s like, “I don't know, the fish,” like well what – I don’t care.  And well, what wine should we get?  Just get a cheap one, it’s all the same to me.  Because all of the – with wine taste – wine, quote-unquote, tasting, it should be flavoring, wine flavoring.  Because it isn't – tasting isn't what you're doing with wine, for the most part.  It’s all the –

Steve Mirsky:       The volatiles. 

Mary Roach:         Volatiles being released and you hold it in your mouth, it warms up, it gets released and goes up into the – through the internal nostrils [laughter] and opening in the – between the mouth and the nose, the internal nostrils, I love that.  You have two sets of nostrils.  And it’s going up and it’s being read in the nose, so wine tasters, they could just – they could throw away their tongue and still do their job practically. 

Steve Mirsky:       You have this –

Mary Roach:         I mean, there's a little bit of sweet, it’s not to say that there's no – the tongue is completely not contributing. 

Steve Mirsky:       Sure.  Now, you have this great experiment you describe in the book, speaking – you have a whole bunch of information about wine in the book, and our experience of it, and you have this experiment, you talk about where some wine tasters were given a white wine that was colored red, and they were careful to make sure that the coloring didn’t change the flavor at all. 

Steve Mirsky:       Right, this was – and I love that it was in France, the University of Bordeaux, so we're talking wine people, and these were – it was wine students at the university, I mean they were – these were high level wine people.  But they're given a red and a white wine, and they're told to write down descriptors, as one does with wine, all the different flavors.  What are you getting from this wine?  So there's a red and a white, and then they're given another pair, and this time the red wine is actually the very same white wine they just had but with that red coloring, and here again, they’ve tested to make sure the coloring isn't changing anything in terms of the flavor, and now these people are using red wine descriptors. They've stopped applying the white wine descriptors.  They think that it’s red wine, and it’s not to say that they're fools or phonies, it’s just that they're – they were letting their – the visual information trump what their nose was telling them.  So I mean, we're just very visually oriented.  We just tend to rely on visual cues, we process them more quickly, so they thought that the white wine was red wine, just because it was red. 

Steve Mirsky:       That's really amazing, because this – their assumption about what it’s going to be changes their perception of – which you would think would be just a completely instinctual response, but it’s not. 

Mary Roach:         No, and I liked – and I've – I had heard about this study years ago, but when I actually got the study, and saw that it was done in this wine region by students in a wine – what's that, oenophile, what's that, O-E-N, oenophile, I don't know, oenophile how the hell do you pronounce that?  But they were oenophiles [laughter] those people.  They should’ve known.  It’s not – so it’s not just like they sat down Joe Schmoe from the trailer park and said, “Hey, describe this wine for me.”  Not to say that people in trailer parks are not connoisseurs of wine, that was not fair of me because you know. 

Steve Mirsky:       But Joe Schmoe from the trailer park might actually have done better on that test, because you point out in the book that the novices can be more discerning than the people who have a lot of information coming in. 

Mary Roach:         Yeah, I tried out for the – there was an olive oil taste panel up at UC Davis, and they announced on their website, tryouts.  Which to me is like an invitation to humiliate yourself, so I’m right there, whether it’s cheerleading tryouts or whatever it is, I’m there, humiliate me.  So I went up there and I said – well, first I e-mailed the woman, Sue Langstaff, was organizing it, and I said, “I don’t have a – I don’t have any background in the olive oil industry, I have no experience, is that OK?” and she said, “No, I want people like you because it’s easier to train a know-nothing than a know-it-all.” Because if you're – if you’ve been in the industry, you think you know everything there is about the flavors of olive oil.  She said, “I want people I can train,” so yeah, you're right, having a quote-unquote experienced palate or trained nose isn't always what – isn't always the best thing. 

Steve Mirsky:       So let's move down the alimentary canal, which is what they called it when I went to school.  Apparently now it’s the digestive tract. 

Mary Roach:         Well, it is the digestive tract, but my sense of alimentary canal is that it included the above-the-neck stuff, as well, it was that whole – you know in the antacid ad where they show the guy with his head turned to the side and the tube goes form the mouth all the way down, that's what I’m thinking alimentary canal, the whole thing.  And that may be wrong, but that's why I chose it.  It’s a little old timey, I also like it has that kind-of cruising down the Danube feel, the alimentary canal. 

Steve Mirsky:       Canal. 

Mary Roach:         I spent my summer on the alimentary canal. 

Steve Mirsky:       Plus, you get all those bad Sherlock Holmes jokes.  Alimentary, my dear Watson, right? 

Mary Roach:         Exactly.  You'd be surprised how many people mispronounce.  I’m getting like, a-limentary, people say a-limentary. 

Steve Mirsky:       Wow, interesting.  Never heard that one.  So further down the canal, you’ve got your arm sticking into a live cow’s stomach.  Tell us about how that came about, and how come the cow is cool with it? 

Mary Roach:         It’s a fistulated cow, or a holey cow, as they – these students, the again school students like to call them the holey cows.  A fistulated cow is a – it’s an educational item, you put your arm in and you feel, first of all, inside the rumen, it’s fermenting.  It’s a composter, it’s hot in there.  The cow is breaking down its food by bacterial action, it’s not the same way we're using gastric acid and enzymes, the cow’s got a fermenter going on.  Plus, you put your arm in there and you feel these un – these amazing contractions.  I actually was worried by – a finger would break.  It was really that powerful. 

Steve Mirsky:       Strong. 

Mary Roach:         It’s like this industrial mixing machine going on, and there's just waves of these powerful contractions, so it’s a pretty instantaneous and amazing and unforgettable introduction to the digestion of animals other than us.  This came about- I don’t remember exactly why I ended up there, but I guess it was – I guess I – there's a part, portion of the book where I’m talking about animals that are feast or famine, they tend to be – the big – it’s either you’ve got a fermenting process where you need a lot of material to get a bit of nutrition, so you’ve got to take in a bunch of stuff, so you have a big – great, big fermenting device.  Or in the case of a predator, like a lion, your – you’ve got a very compliant stomach, as in it stretches out.  You can hold – you can take down a gazelle, pack it all in and lie around in the sun and digest for a few days, because nobody’s going to mess with you.  So you’ve got – to you tend to have – you have just different animals, depending on their environmental niche, will have a different type of compliancy to the stomach.  And so I guess that was – it was in that mix that I ended up with my arm in a cow’s rumen.  But – and I had gone there, I don't know why, when I go and do an interview, I feel like I need to look presentable, and I'd worn like, a skirt and kitten heels and I show up and they're looking, and it was like, “You're going to have to put some shoe covers on, and there's a lot of manure here, are you sure you want to do this?  All right, follow me,” and they were just – they're wearing muck boots and feed hats and so here I am.  There's photographs that just crack me up. 

Steve Mirsky:       Well, they didn’t know that you're the woman who went to that tomato-throwing festival in Spain many years ago. 

Mary Roach:         Oh yeah, La Tomatina.  That's right.  Wow. 

Steve Mirsky:       I remember, you wrote about it for American Airlines, in-flight magazine.  Once you’ve done that, you'll do anything. 

Mary Roach:         That – you end up at the end of the tomato fight, you are – I remember lying down, it was like a foot and a half of tomato salsa, basically [laughter].  The streets are running with salsa, and the most amazing thing about La Tomatina, this crew of people come out with these wooden pushers and they push it all into this – the sewers of that town are unbelievable, because they push that stuff – it was gone in a couple hours, you would never know.  Little bits of tomato here and there.  But anyway, that – yeah, I'll – another unforgettable experience. 

Steve Mirsky:       So we've got you in the cow’s stomach, let’s move on down a little further, and again, you did not engage in hooping, but you spoke to a really top-notch hooper.

Mary Roach:         I did.  Hooping is smuggling contraband in the rectum, using the rectum for the purpose for which it evolved, it’s a storage device.  It’s a – you – which is – you should be grateful that you have this storage facility, that you don’t have to immediately find a place to deposit what's coming down the line.  So it’s a very accommodating, as it turns out, storage facility.  There are – the folks at Avenal State Prison let me come down and talk to – not only to the people who deal the interdiction I guess is the proper pronunciation, those folks, but also I interviewed a guy who was known to be a pretty brave and accomplished hooper, as in through the hoop, through the ring.  That's where hooper comes from.  And I – we sat down and had an unusual conversation [laughter].  Well, unusual for me.  I got the sense that for him, it was – I mean, everybody does it in prison.  I mean, it’s just – the rectum is a – it’s a pocket, it’s another pocket.  It’s just not – I saw video footage of a visitor’s room where there was a guy sitting with his family, he’s playing a board game with his son and his wife passes off a little packet to him.  He reaches back behind himself and puts his arm down his pants, and it’s just as though he’s putting his phone or his wallet back in his pocket.  It was that fast and nothing went across his face, just like, let me – hold on, let me put that away for you.  Just it’s a – just a way of life, and – but it takes a little getting used to, because the rectum is, of course, not used to things coming in from that direction frequently, in most cases.  So there's a little bit of training they – that they do, walking around the cell, holding [laughter] things. 

Steve Mirsky:       And this guy had done what, three cell phones at the same time? 

Mary Roach:         He had done – well, god, this was a – he – this – I don’t – he said it was done on a bet.  Someone else said it was – I'm not sure why, but he had taken two – it was two antiperspirant containers on either end of a cardboard tube, taped it up, it was a – size of a large – it was like a big yam.  Big, large object that had been – this – [sirens wailing]

Steve Mirsky:       I think they're coming for him right now [laughter]. 

Mary Roach:         This had created a medical situation and it had to be removed.  So he was notorious for his hooping abilities. 

Steve Mirsky:       And the reason he did it was you – if you could smuggle contraband into the prison that you pick up during visitors hours or whatever, and there's a black market for it within the prison. 

Mary Roach:         Correct. 

Steve Mirsky:       Or brown market. 

Mary Roach:         Brown market [laughter] that's right.  Exactly, they – tobacco is the most common item.  They would find whole bags full, they call them spindles of – it’s just a – it looks like a yam, it’s – and it’s in latex, and they are smuggled in and sold, it’s a hugely inflated black market price.  And cell phones are smuggled in because that enables you to do business deals and run your gang from in the prison, and that's frowned upon, so you get – and smartphones is a – smartphones are a lot larger, so it’s gotten tougher to be a hooper.  Back in the days of there were a couple of little phones that were very good.  I think the sales of some of those little tiny phones that came on the market ten years ago, huge numbers of those were confiscated because they're easier to – they're more comfortable.  It’s a more comfortable load. 

Steve Mirsky:       Sure, you do you want to try to get the Galaxy S3 in there [laughter]. 

Mary Roach:         No. 

Steve Mirsky:       So you talk at the end about – you and I have had a similar experience.  We have been privileged to be awake through an endoscopic procedure.  For you, it was a full colonoscopy.  For me, it was a sigmoidoscopy, and actually look through the viewfinder there, and so I – you talk about having your head up your ass.  But I – when I did it, I thought of it as like an Escher painting [laughter].  And one of the amazing things is just how pink and clean and shiny and beautiful it is. 

Mary Roach:         Did you ever see the movie Galaxy Quest? 

Steve Mirsky:       Of course. 

Mary Roach:         There's this scene when what's-his-name, Tony –

Steve Mirsky:       Shalhoub. 

Mary Roach:         Shalhoub.  He – they – when he first comes on this spaceship and the doors open, he goes, “It’s so clean.” [Laughter] Like that's what's going through my head, it’s so clean.  It was, it was – of course it’s been heavily cleaned prior to the procedure, but it’s just – it’s pink and shiny, it’s like a new car, it’s like a – what's that –

Steve Mirsky:       It does not have that new car smell, though. 

Mary Roach:         It does not have that new car smell.  What is it you get, the – is it the Avon lady, who is it that gets the pink Cadillac?  It’s not Avon. 

Steve Mirsky:       It'll come to me. 

Mary Roach:         Same here, anyway, but it’s like, it’s a – it’s this beautiful –

Steve Mirsky:       Two names like Mary –

Mary Roach:         Mary Kay Cosmetics, thank God, because that would've been bugging me all day. 

Steve Mirsky:       Good, I’m glad we've equated them with the lower colon. 

Mary Roach:         And it’s not often I get to work Mary Kay into an interview, so. 

Steve Mirsky:       I got to tell you mind, like we said, pink, shiny, beautiful, but on one of the little rings of muscle, just sitting there, holding on for dear life, one, tiny, solitary, green pickle seed. 

Mary Roach:         Really. 

Steve Mirsky:       It’s hilarious. 

Mary Roach:         A little – and you ID'd it as pickle, not sesame seed, not –

Steve Mirsky:       Well, my doctor did. 

Mary Roach:         Your doctor. 

Steve Mirsky:       He said, “You had a pickle recently.”

Mary Roach:         They – I think they get a kick out of that.  And I – when I was – I would – for part of the book, I was at a place where they were putting – they were preparing the material for a fecal transplant.

Steve Mirsky:       Yes. 

Mary Roach:         And I remember the guy who was preparing the substance calling out recognizable elements, like peanut, [laughter] there's chili pepper, I’m thinking kung-pow chicken. 

Steve Mirsky:       Exactly. 

Mary Roach:         So it’s like this little forensic, I don't know what the term – forensic alimentary detective work going on. 

Steve Mirsky:       We had a whole show on fecal transplants with Maryn McKenna recently, so I won't ask you to go into that, but the last chapter of the book discusses fecal transplants at length.  I abhor Fox News, and any chance to show the kind of nonsense that they purvey is great, and you have a section in the book where you speak to an expert who talk about somebody who said on Fox News that if a terrorist put a bomb up his rectum, he could take down a plane, and you're expert says that that was – I think it was hogwash or something like that. 

Mary Roach:         Codswallop. 

Steve Mirsky:       Codswallop. 

Mary Roach:         I think it was a breast implant they had a piece about.  Well, there were a couple of them, but there was one that was saying that they – you could put the bomb in a breast implant, or love handles, that was another one.  Love handles, that they were surgically implanting bombs in love handles.  Codswallop, I love that [laughter]. 

Steve Mirsky:       You said that it would at most, destroy the seat you're in but it couldn’t take down a plane. 

Mary Roach:         Right, your body would absorb – it’s like ten – there's a ten fold decrease in the effectiveness of the bomb if it’s inside the body.  You're very effectively going to destroy that body, most of those bombs are working with the shrapnel and the nails and things that are in them.  You're not going to – and even if you blow out a little hole, blow out a window on a plane, Myth Busters did that, where they showed that even if the plane depressurizes, as long as people have oxygen, they can fly that thing.  It’s not going to blow up.  So it’s just – the wings are on there and the pilot’s OK, you're coming down, I mean, intact [laughter]. 

Steve Mirsky:       You're landing safely. 

Mary Roach:         You're landing safely, that's right. 

Steve Mirsky:       You point out in the book every hospital [laughter] has an ass box.  There's an episode of Scrubs where somebody thinks that it’s the lost-and-found box, [laughter] and the nurse says, “We don’t have a lost-and-found box.  We have an ass box.”

Mary Roach:         The ass box, yeah.  This was a – it was Anna Dhody, the Mütter Museum curator.  Gosh, the Mütter Museum in Philadelphia has this fabulous collection of anatomical oddities and weird medical devices and instruments and things, and we got – she’s the one that said, “Yeah, every hospital’s got an ass box.”  But – and I checked, I put on Twitter, I said, “Hey, ER people, medical personnel, is it true, every hospital have an ass box?”  Some of them now just have files of the x-rays of the thing that was up the ass.  They don’t actually necessarily keep the – which isn't nearly as much fun. 

Steve Mirsky:       I guess we should say the ass box is the box that the emergency room people put everything that they take out of people’s rectum, that wind up in the emergency room. 

Mary Roach:         Yeah, that's right. 

Steve Mirsky:       Some fascinating items. 

Mary Roach:         Fascinating items, yes.  Cow’s horns, jeweler’s saws, plantains.  One [laughter] guy – there was some paper that had multiple holdings under the term collections, which I liked.  One guy had 402 stones.  The other collection I liked was lemon and cold cream jar. 

Steve Mirsky:       Wow.  So [laughter] what's your next book going to be about? 

Mary Roach:         I honestly don’t know, Steve.  I really – what the – I don't know.  I’m not sure, I don’t have another –

Steve Mirsky:       You'll wait until the muse taps you on the shoulder. 

Mary Roach:         Yes, I’m not there. 

Steve Mirsky:       Well, everybody, you got Elvis’ colon, you got the doctor-patient relationship where the guy had a fistula in his stomach and the doctor is just basically keeping him as a 24-hour-a-day test subject, licking to find out what the acid quality is.  It’s everything from the nose to the other end of your canal, it’s a lot of fun, everybody should go out and buy it immediately. 

Mary Roach:         Immediately, under penalty of law [laughter]. 

Steve Mirsky:       Mary Roach’s new book is Gulp: Adventures on the Alimentary Canal, and it’s available as an audiobook on Audible.com.  For a free book and trial membership, just go to Audible.com/sciam.  And for all things Mary Roach, visit her website, MaryRoach.net.  Well, that's it for this episode.  Get your science news at our website, www.ScientificAmerican.com, where you can check out Jennifer Fraser’s article on what critters are living at the bottom of the Marianas Trench.  By definition, the ones with mouths have trench mouth.  Sorry about that.  And follow us on Twitter, where you'll get a tweet whenever a new item hits the website.  Our Twitter name is @sciam, S-C-I-A-M.  For Scientific American’s Science Talk, I’m Steve Mirsky, thanks for clicking on us. 

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