Time maybe for a radical re-jigging of the scorch model – and of the alleged superficiality of the Shroud image too?

I’ve been exchanging emails with Hugh Farey recently. He’s been sending some impressive photographs of linen fibres,  before and after scorching. There’s currently the  beginnings of an exchange of views on the importance or otherwise of the primary cell wall (PCW) in capturing the Shroud image (well, scorch imprints anyway).

Regular visitors to this blog will know by now that my preferred working model for the  faint yellow/brown TS  body image is a contact/conduction scorch aka thermal imprint, with no role for radiation of any kind, while keeping an open mind on other possible mechanisms that are capable of being investigated  by the scientific method, i.e. model-testing.

Hugh’s comments have prompted me to spend a few more hours with the new microscope. Trying to arrive at firm conclusions as to what one can really see and what is an artefact is tricky, given the (double) light refraction, i.e. birefringence of internal cellulose fibrils,  that makes it exceedingly difficult to focus on fibres, the latter being being  macroscopic 3D entities. visible-to-the-naked eye unsectioned 3D entities (big and plump in other words). What’s more, at the risk of getting overly techy,  my microscope lacks crossed-polaroids, handy for detecting those nodes, as well as regions of high crystallinity, such as the highly-organised cellulose fibrils of the thick internal secondary cell wall and generally giving a sharper, crisper image.

But I have seen enough to make me realize that I have up till now been operating with an over-simplified model, one that imagines that the secondary cell wall (SCW) is entirely cellulose, and that TS image-acquisition must ipso facto have been confined exclusively to the primary cell wall (PCW). That simple model has its advantages in theoretical terms, i.e. in pursuing a link between the (allegedly) highly superficial Shroud image – estimated as 200 – 600nm thick and a scorch confined to the PCW – assuming the latter were of approximately the same thickness.

But that model now seems hopelessly – and misleadingly – simplistic, and indeed may be placing a constraint on developing hypotheses re the mechanism of imprinting of the TS image, not just the scorch model.

Here’s a graphic I have just cobbled together on MS Paint which summarises the new thinking. Note the importance attached to the fact that some 15% of the linen SCW is NOT  heat-resistant cellulose, but chemically-more reactive non-cellulosic polysaccharides (NCPs) which should (in theory) be just as capable of acquiring a scorch – albeit a faint one  if interspersed with cellulose – as the PCW.

See Morvan et al (2003) pdf

Idealized versus real secondary cell wall linen fibre

I’ll stop here for now, while I do some back- of- envelope calculations on what proportion of the Shroud image intensity might be on a faint and difficult-to-spot be- sure-about coloration of the interior SCW, as distinct from a more readily visible intense coloration of the enveloping but highly superficial PCW. Get my drift?  Yes, we really do need fibre cross-sections, as per diagram above. That needs embedding in wax and microtome sectioning, probably, nay almost certainly beyond my means. Hugh? Thibault?

I’ll be back later to post Hugh’s pictures and comments, as well as some more thoughts on the revised model above. Now then, what’s that formula for the volume of a cylinder, 4pi r squared as I recall.


Late addition: (now the arithmetic, are you sitting comfortably?) there are two ways of approaching the question of how much incident light is absorbed by the PCW (or, more optimistically,  the Shroud image, determining how each  “looks” to the observer, and also where the image would appear mainly to be situated when viewed under the microscope in  “as-is” (unsectioned) specimens. The first is by using scattered light, with incident light beamed onto the surface of the specimen, the other is transmitted light, with the light source behind or underneath.

 The latter is by far and away the easier to analyse, so I’ll deal with it first, even though I think it the less realistic of the two scenarios. Light from behind encounters a maximum light path that is first a thin PCW, then the thick SCW, then the second PCW. Let’s make a few approximations, i.e. that the PCW is 200nm thick, and the SCW has 50 times that figure as diameter/light path. Let’s further assume that 80% of the PCW is easily-scorchable polysaccharide, and the comparable figure for the SCW being 15%, representing the non-crystalline non-cellulosic polysaccharide. The ratio of visible light absorbed by PCWs to SCW is then 1:4.7, or, roughly speaking, 5 times as much in the SCW as the PCW. But as the diagram above shows, it is the PCW that might seem to be the major absorbing layer based purely on image density, and the fact that the observer always sees the SCW through the PCW, i.e. the latter is the face that leaves the greater impression on the senses. So “SCW”  light absorbance and thus image density  could easily be mistaken as part of the PCW’s. (N.B. everything here refers to viewing an undamaged fibre; the Adler/Heller/Rogers experiments, where “clean” and reportedly colorless fibre cores are stripped away, leaving coloured impressions (“ghosts”) in sticky tape adhesive are another matter that will be scrutinised more closely soon, not necessarily on this post.  For the moment, one has to ask whether a surface colour many times more intense than the interior might not have led to a false conclusion from those ‘strip-away’  tests that ALL the Shroud image colour was in the topmost layer, despite the latter being too thin to resolve under a light microscope, giving rise to that “200nm” figure, or as others, notably Adrie, see her recent comment,  prefer (<200-600nm).

For that reason, the analysis based on light that is reflected/scattered off the image is likely to be skewed even more in favour of the more superficial PCW envelope, even if the  SCW  were to account for the majority of scorched polysaccharides, in terms of total amount. But don’t expect any quick estimates of the proportion of reflected light from PCW and SCW respectively.  Performing that calculation almost is going to need some outside help.

As ever, this blog is to be viewed as a work-in-progress,  not written on tablets of stone (meaning I shamelessly add on new bits, and occasionally change or delete the first part).  Yaboo sucks to Shroudie news aggregators/news managers who might have preferred a fait accompli from which selected passages could be quoted,  – to say nothing  about omitting the troublesome  bits that might offend those regulars seeking reinforcement of a certain agenda, one that views the TS as a handy aid, a prop, in bolstering and/or proselytising their own brand of religious belief.  😉


As promised, here are cut-and-paste accounts from my email inbox of  Hugh’s recent researches together with attached photographs,  inserted into text close to – but not always right next to – relevant text.

The first: dated Wed 9th Jan:

“To be honest I’m not sure what birefringence is, but I think it may be a definitive test for impurity layers!

I enclose two photos from a bit of linen, clean at one end and scorched on the other.

Caption later

1) Sticky tape sample of scorched linen between crossed polarisers – X40

I stuck a piece of sellotape firmly down over the whole thing, pulled it off and then stuck it to a microscope slide. The dark blue bubbles are from the sellotape. Anyway, with bits of polaroid below and above, and a magnification of 40X, this is what we see. The linen fibres show up brightly against the dark blue, and stuff which isn’t linen (any other impurity) doesn’t. You can see on the ‘scorched’ slide lots of regularly spaced patches of little lines, representing shreds of fibre (not, I think whole bits of broken fibre, but shreds from the surface of fibres – your beloved PCW?) torn off by the sellotape. The ‘clean’ slide shows no such patches, as the linen is not sufficiently degraded to pull fibres apart.

2) Sticky tape sample of fresh linen between crossed polarisers – X40

So – if the image is on an impurity layer, which does not show up in crossed polarisers, then an ‘image’ tape will look like a ‘non-image’ tape, and rather like my ‘clean’ slide. But if the image is on the fibres themselves, then an ‘image’ tape will look like my ‘scorch’ tape – even if the image is not a scorch.”

Are there any tapes out there which haven’t been returned to the Vatican? Do encourage anyone who has got one to try the test!”


2nd  email: Thur 10th Jan:

“I think the thin coloured layer is really there.

Caption later

3a) Scorched part of single fibre – X400

The first two pictures are of the same fibre (the right side of the coloured one overlapping the left side of the white one) at 400X, and the colour is clearly present between the nodes.

Caption later

3b) Unscorched part of the same fibre – X400

It also shows the variation in colour possible along the length of a single fibre. The third photo (40X) shows those patches of separated fibre fragments I showed in the polarised photo, coming off the uppermost surfaces of the uppermost fibres of the uppermost threads, which, again, are coloured throughout.

Notice that even in a 1/1 ordinary weave, on one side the warp threads are prominent and the weft threads depressed, so only the upper surfaces of the warp thread fibres have broken away, which is why all the patches have lines pointing the same way. On the other side, the cloth appears much flatter, and I dare say if I had singed that side the patches would have been closer together and alternated directions at right-angles.

Caption later

4) Sticky tape sample of scorched linen (as photo 1) in transmitted light – X40

4) Sticky tape sample of scorched linen (as photo 1) in transmitted light – X40

By rubbing hard on the sellotape after it is stuck to the slide (with the principal intention of being able to focus at high magnification), it is quite easy to smash individual fibres (I think these are ‘bast’ fibres) apart into their ‘elementary fibres’ (see the diagram at http://www.agrofibrecomposites.com/process.htm), and the fourth attachment shows a scorched (bast) fibre literally bashed to bits. These bits are roughly cylindrical and 10-20um wide (I read).

Caption later

5) End of a single scorched fibre showing broken microfibrils – X1000  (edited)

5) End of a single scorched fibre showing broken microfibrils – X1000

This is considerably thicker than Rogers’s putative 200-600nm, but I am not convinced by his photograph (in his FAQ paper) of two ‘troughs’ in a layer of sellotape glue. I think it possible that the colour difference is an artifact of the focusing, and I’m afraid that if that is the best image he can produce, its not sufficiently convincing for me. My idea of the ‘image layer’ (of broken off ‘elementary fibres’) is much more clearly discernible and speaks for itself.”


Third email, in response to my:  “Superb pictures  – and thought-provoking comment too. May I use this and your previous email, pictures included, as topics for posting – thus helping to keep the kettle on the boil so to speak?”

Hugh: “Yes indeed, help yourself, as usual. I normally post direct to your blog anyway, as you know; it’s just sending photos that I use email for.”


Final note: for now, at any rate: I’m aware I have not really addressed the reference in the title to the Shroud image per se, and explained fully why I consider these thoughts on PCW v SCW  NCPs to be relevant. I could do so, though it would involve expressing (still further) irritation with Ray Rogers’ compressed style of exposition, and having to analyse it line by line, sometimes word by word, in an attempt to extract his precise meaning.  All that takes up more space. I’m now minded to make a separate posting of it, linking to this one, but if anyone’s keen to know my thinking re the Adler/Heller “ghost” experiments with sticky tape and their “image colour on surface layer only” conclusion, one that was supported by Rogers, then I would be more than happy to discuss that under comments.

PS:  Hugh’s observations above are based on some highly adept handling of his sellotape, crossed polaroids etc. There’s some fascinating detail packed into those summaries, and he may well have hit on a method for distinguishing between an image on the surface as against one that is more integral with the fibre (some convergence there?). Since my head is buzzing right now with some of the new interpretations based on my own “impure SCW cellulose” model above, and on Hugh’s, placing a question mark against exclusive PCW imaging, I’ll  hold off saying any more about Hugh’s findings right now, and give all the new perspectives, Hugh’s and my own, time to digest. Sorry about the wordiness – but there are some tricky issues here. Oh how I wish we had cross-sections to examine, as mentioned earlier. Does anyone know if the STURP investigators (Adler? Heller? McCrone?) ever sectioned and examined cross-sections of, say, wax- embedded threads and/or elementary fibres?


About Colin Berry

Retired science bod, previous research interests: phototherapy of neonatal jaundice, membrane influences on microsomal UDP-glucuronyltransferase, defective bilirubin and xenobiotic conjugation and hepatic excretion, dietary fibre and resistant starch.
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32 Responses to Time maybe for a radical re-jigging of the scorch model – and of the alleged superficiality of the Shroud image too?

  1. Hugh Farey says:

    My microscope doesn’t have polarised filters either but I happened to have a couple of squares which I simply piled above and below a slide. What I can’t easily do is rotate them. You can get them from sciencestore.co.uk for £6 or so, but to my surprise, as we started the Lent term several children returned with what looked to me like comic plastic spectacles. They were from 3D cinemas, and as the children had no use for the lenses, they had just pulled them out and threw them away! Luckily I managed to retrieve a few.
    Just as a control, yesterday I smeared some gravy browning (sorry, ‘ammonia caramel’) onto some linen, let it dry and stuck sellotape on it. Sure enough the colour came away, but the little patches do not shine in crossed polarisers.
    Finally, the papers last week were full of a new portrait of Kate, Duchess of Cambridge, full face, with a very dark background. By superimposing it, with a bit of stretching, onto the Enrie negative, it is easy to prove conclusively that she is a direct descendant of Jesus and probably has a glass of wine from the holy grail every evening with Leonardo da Vinci. Remember you saw it here first…

  2. colinsberry says:

    🙂 You did say that school of yours was for boarders, didn’t you Hugh? Methinks one of your charges must have slipped something into the staff sugar bowl…

  3. Hugh Farey says:

    I neglected to mention that the fourth picture (fibre bashed to bits) is at 1000X. It is those little broken plank-like pieces that come off and stick to the sellotape making the little patches of brown lines in the previous 40X picture.

  4. colinsberry says:

    Thanks Hugh. Any chance you could supply captions to accompany each of your pictures?
    I’ve just added this to the end of the posting:

    “PS: Hugh’s observations above are based on some highly adept and resourceful handling of his sticky tape, crossed polaroids etc. There’s some fascinating detail packed into those summaries, and he may well have hit on a method for distinguishing between an image on the surface as against one that is more integral with the fibre (some convergence there?). Since my head is buzzing right now with embryonic new interpretations based on my own “impure SCW cellulose” model above, and on Hugh’s, placing a question mark against exclusive PCW imaging, I’ll hold off saying any more about Hugh’s findings right now, allowing time for thoughts to gel.

    Sorry about the wordiness – but there are some tricky issues here . Oh how I wish we had cross-sections to examine, as mentioned earlier. Does anyone know if any of the STURP investigators (Adler? Heller? McCrone?) ever sectioned and examined cross-sections of, say, wax- embedded threads and/or elementary fibres?

  5. Hugh Farey says:

    1) Sticky tape sample of scorched linen between crossed polarisers – X40
    2) Sticky tape sample of fresh linen between crossed polarisers – X40
    3a) Scorched part of single fibre – X400
    3b) Unscorched part of the same fibre – X400
    4) Sticky tape sample of scorched linen (as photo 1) in transmitted light – X40
    5) End of a single scorched fibre showing broken ‘elementary fibres’ – X1000

  6. colinsberry says:

    Thanks Hugh – have now added them.

  7. colinsberry says:

    PS: might not 5 be described as a thread, or rather part of a thread, in other words a skinny fibre-depleted thread, given the relative paucity of elementary fibres? I’m assuming it is not an elementary fibre showing cellulose fibrils. Or is it – given the very high (x1000) magnification?

  8. Adrie says:

    Hello Colin,

    To answer your question: “Al Adler mounted image fibers in plastic and cut sections normal to the length of the fibers. He did not see any color in the cellulose.” (Dan in his posting of May 7, 2012; see also my comment). It was the second of “Adler’s observations” (plural) mentioned by Rogers in FAQ 12, p. 11, of which he only described the first one (the ‘diimide observation’). I haven’t found the ‘cross section observation’ in the compilation of Adler’s articles in The Orphaned Manuscript.

    BTW, ‘ghosts’ were also pulled from non-image fibers of the Shroud: “Phase-contrast photomicrographs show that there is a very thin coating on the outside of all superficial linen fibers on Shroud samples named “Ghost”; “Ghosts” are colored (carbohydrate) impurity layers pulled from a linen fiber by the adhesive of the sampling tape and they were found on background, light-scorch and image sticky tapes (Zugibe and Rogers 1978, Rogers 2002).” (Evidence A3, p. 4 of Evidences for testing hypotheses).

  9. Hugh Farey says:

    Nomenclature can be a bit of a problem. I’m using the word thread to mean the product of spinning flax fibres together, the thing with the Z-twist in it. Threads very rarely get pulled off cloth samples by sticky tape unless they are very short (from a cut sample) or very damaged. Fibres are what the threads are made of, and appear to be the product of whatever treatment flax plants are given to turn them into something spinnable. They can be of different thicknesses. Photo 5 is the end of one of these fibres. Fibres, according to http://www.agrofibrecomposites.com/process.htm, are made of ‘elementary fibres,’ which in turn are made of microfibrils.
    Adrie: thanks for that. I’ve been trying to get hold of a copy of the Orphaned Manuscript but so far without success. Italy is a bit slow in postal delivery! Do you happen to know if the ‘ghosts’ were examined between crossed polarisers? That would establish whether they were bits of degraded flax, or an added coating.

    • colinsberry says:

      So if I understand you correctly, Hugh, your photo 5 is of a highly magnified (x1000) fibre, aka elementary fibre, just one of scores in a thread. What one sees inside are not fibres, but fragmented cellulose fibrils, those break points not to be confused with the nodes/dislocations of linen/flax elementary fibres. Have I got that right?

      • Hugh Farey says:

        No, I think photo 5 is an ‘unqualified’ fibre, and the broken plank-like thingies are bits of ‘elementary fibre.’ I think you’d have to go to SEM for microfibrils. I think fibres, elementary fibres and microfibrils all break just anywhere if sufficiently degraded, which these are.
        You’ll have seen my response to Adrie on shroudstory. I’ll send Dan a couple of blow-ups of Rogers’s photos, and maybe a couple of my own for comparison.

        • colinsberry says:

          It’s my understanding Hugh (correct me if I’ve misunderstood) that if you take a thread from linen, and tease it apart, you will see scores of individual fibres that are easily visible with the unaided eye, but which need a microscope to see internal structure. It is these fibres that are described as “elementary fibres” in the literature. That may be in order to distinguish them from bast (stem) fibres in unretted flax stems that are bundles of those same elementary fibres but cemented together with pectin etc. Retting rots away the latter, releasing the elementary fibres that are spun into multi-fibre threads for weaving

          Now then, when you look at a linen elementary fibre under a microscope, low power, maybe with polaroids, in addition to the nodes aka dislocations, then you may, if you’re lucky and focus carefully, be able to see the microscopic strand-like structures within the elementary fibres that are cellulose fibrils. So one does not need SEM merely to detect the presence of cellulose fibrils – only to see their fine structure. I’ve seen references to microfibrils and even nanofibrils. Maybe it’s those you are thinking of, and maybe equating “elementary fibre” with fibril or microfibril? An elementary fibre is one or more elongated nucleated cells, fused together. A fibril is at the subcellular level.

          So, to summarise: given the high magnification of your photo 5, I don’t think it’s a thread you see there with its elementary fibres. I think it’s an elementary fibre, showing internal, closely packed cellulose fibrils. First, compare with your x400 pictures which you agree show single (elementary) fibres – NOT whole spun threads comprising scores of fibres. Secondly, your picture 5 shows bundles of our contentious ‘wotsits’ that are SHEATHED. There is no sheath on a thread, but the fibrils of an individual elementary fibre ARE within some kind of sheath, presumably the primary cell wall, and the bundle of cellulose fibrils collectively comprise the secondary cell wall..

          What do Adrie (and Thibault if he’s around) have to say I wonder? One thing’s for certain. It’s important we get the nomenclature right, if we are not to talk at cross-purposes.

          PS I think you mean response to “Andy”, not Adrie. I’m planning a post for tomorrow to counter his weaponised Rogers – which he deploys in a trademark atttempt to shut down off-message debate (his message, needless to say)…

          • Hugh Farey says:

            Aaaaaah! (Sound of penny dropping). So I thought the things people spun with were “bast fibre bundles,” but actually they had been separated in the retting process and are in fact individual or ‘elementary’ fibres. Got it at last. Revised caption to photo 5…
            5) End of a single scorched fibre showing broken microfibrils – X1000

          • Thibault HEIMBURGER says:

            Yes, I am here.

            Too much to say right now !
            But in any case, very interesting.

            For the time being, I am looking to Hugh’s beautiful photos and comments.
            I have posted on “the other site” my answers to some questions of Hugh.

            My comments/answers, peer-reviewed papers on the PCW and photos later.

            Best regards.


  10. colinsberry says:

    Thanks profusely Adrie – I had seen that posting of Dan’s, but had failed to make a proper mental note of that crucial detail re a transverse section, probably due to all the other distractions and wrangles (Valencia, Dawkins challenge, what Rogers had really meant but didn’t quite say etc etc). The question I ask myself is whether the interior of the fibre really was devoid of colour, or only seemed that way, relative to an intense coloration on the surface. A faint colour in the interior could/might still account for a lot of total light absorption, at least by transmitted back-light across the entire diameter of the fibre, on account of the relative dimensions of SCW and any sub-microscopic surface layer (PCW or acquired coating) as proposed in my posting.

    Re your second para, I am deeply curious to know how one could detect ghosts in adhesive from non-image fibres if they are : (a) below the resolution of light microscopy and (b) uncoloured. Maybe you can illuminate (no pun intended) or help me visualize (pun intended) 😉

  11. colinsberry says:

    Drat. You give in too quickly. Now we’ll have to find something else to disagree about. Liked your comment however about the medullas on T’Other Site, and had drafted something rather similar for tomorrow’s post. Ray Rogers, gifted chemist though he could be when properly tuned in, was a great one for setting up diversions and road blocks that take hours to make sense of. In fact, I suspect your misunderstanding re bast and elementary fibres could have been due to that Cardamone diagram he inserted into his FAQs. It had me confused for a long time too…

  12. colinsberry says:

    Hello Thibault. Greetings. I’m not sure what I have to say to you right now regarding the science. It’s your prerogative to dismiss scorching at each and every opportunity, but what do you have to put in its place? Sorry to be so blunt, but I don’t believe in beating about the bush. Scorching ticks a lot of boxes for me – see the banner at the top of my posts – so I don’t know how you can be so categorical that scorching played no part in the making of the TS, whether it was a 1st century or 13th century event (I prefer the latter, needless to say, feeling that the radiocarbon dating could not have got it so wrong as to confuse those two).

    Again, I ask, what is your preferred model, assuming that you have one?

    • Thibault HEIMBURGER says:

      Hello Colin,

      What are you speaking about ?
      I do not understand some typical English sentences like ” I don’t believe in beating about the bush”.
      Would you be kind enough to use basic English with me please ?

      I have absolutely no preferred model.
      But I have seen myself that scorching does not work in the REAL world.

      In any case, I try to follow the discussion both on your site and the other site.


      • colinsberry says:

        In the REAL world of scientific research,Thibault, it is better to have a hypothesis than no hypothesis. In the absence of a hypothesis, any hypothesis, there tends to be stagnation and failure to pursue new experimental directions . It is through the cycle of hypothesis and experimentation that we gain new and original insights, occasionally breakthroughs if one gets lucky. That’s true whether the initial hypothesis gains traction or has subsequently to be modified or abandoned.

        Working in an area of research for months or years without ever framing an hypothesis with which to plan new experiments, interpret and rationalise findings, counts as failure in my book. Failure is not an option for a professional scientist whose job is to make new discoveries. You chose to treat patients, I chose to make new discoveries and advance new hypotheses and theories. Be as sniffy as you like about scorching, but it’s a hypothesis, which is one more than you presently possess.

        “Beat about the bush”: ne pas y aller par quatre chemins… 😉

  13. Hugh Farey says:

    The ‘locally degraded image layer’ photos in Adrie’s first reference, from a shroud image fibre, are quite consistent with a light scorch. The fibre has been broken into those plank-like fragments of microfibril illustrated in my own photo above, some of which have broken completely away, to leave that gap. The reason the gap is not coloured is not, of course, anything to do with the lumen. It’s an empty space, and empty spaces can’t be coloured. No, the reason the gap is not coloured is because either the microfibrils underneath it are uncoloured (and I find with light scorches that there is no need for them to be), or there are no microfibrils there; after all, this fibre was presumably torn off the shroud, and the tape need not have removed the fibre in its entirety. We are told how easily these tapes came away; this was because the image fibres were sufficiently degraded to break away rather than having to be pulled out like the non-image fibres.
    The picture of the fibre degraded by coronal discharge was formed, we are told, by ironing the cloth. That’s what I call a scorch. I can understand that it may be that a CD predisposes cloth to scorch at a lower temperature than usual, as may coatings of sugar or starch, but to my mind, brown marks made by ironing = scorches.
    As for the ghosts – Is that rather grey, rather grainy photo of two smooth trenches in the sellotape glue the only photo we have of them? I know how different a photo can be from what is actually observed through the eye-piece, and don’t deny Rogers’s or Adler’s observations, but if that is all the evidence we now have – well it’s not much to go on, is it?

  14. colinsberry says:

    Superb comment if you don’t mind me saying Hugh. Not just a breath of fresh air – more like having the windows flung open in a room with a stagnant stuffy atmosphere.

  15. Adrie says:

    Prompted by Thibault’s reply on the Other Site, I searched the Superficiality paper, now online for free. Figures 9B and C and 10-2 (p. 8) show that the color really is superficial: the uncolored substrate still connects the two parts of the broken image fiber.

  16. Hugh Farey says:

    Thanks for the link, Adrie. However (and I’m aware I’m going out on a limb here: my knowledge of the microstructure of linen is entirely superficial…) I’m not sure Fanti et al have interpreted their pictures in exactly the same way as I do, although the effect is perhaps the same.
    My understanding, based on the agrofibrecomposites site which I have mentioned above, is that the structure of a fibre is more complex than a simple ‘PCW – SCW – Lumen’ model, in that the “inner cellulosic material” of the SCW is not amorphous, but itself divided into ‘microfibrils,’ which are the things which have broken up into the rectangular sections we see on Fanti’s photo. I don’t know if each of the microfibrils has a PCW of its own (but presumably they have some kind of structure), and I don’t know if the whole fibre is sheathed in its own cell wall of some kind. It seems to break up quite readily when heated.
    So where Fanti sees a single thin PCW layer coating a thick amorphous SCW with a hole in it, I see a bundle of a dozen or fewer microbrils. Where his PCW is torn away like peeling paint to reveal uncoloured SCW, I see fragments of microfibrils broken away to reveal other microfibrils, which are uncoloured. I don’t think the overall effect of the image, or the mechanism of its appearance, would be very different in either case.
    Having said that, one of Fanti’s threads (Photo 9 and particularly 10 in your link) looks so exactly like a torn PCW sheath around an amorphous core that I am given pause, as they say! I will have to start stressing some more fibres to see if I can achieve the same result, coloured or uncoloured.

  17. colinsberry says:

    You might be interested in this paper from the Journal of Materials Science(1999), Hugh, if you have not seen it already. Only the abstract is available, The abstract alone, and selected free pages (well spotted Hugh!)is interesting, at least to those of us who are intrigued by the report that TS image fibres are fragile and prone to fracture (hardly likely if the imaging process were confined purely to the PCW or an impurity layer).


    The deformation behaviour of single elementary flax fibres was investigated in an ESEM, using a modified loop test. Plastic deformation starts on the compressive side of the loop, whereas fibre failure occurs on the tensile side of the loop. The primary and the secondary cell wall show a different deformation behaviour. The primary cell wall breaks in a brittle manner, whereas in the secondary cell wall, due to its fibrillar nature, a coarse crack grows, bridged by fibrils. The secondary cell wall was found to split relatively easily along the length direction, indicating that the lateral strength of the fibre is lower than its tensile strength, which also accounts for the lower compressive strength of the fibre compared to its tensile strength.

    Bos and Donald

    This paper refers to flax, not linen fibres, and says the fibrils tend only to separate along the length axis, it being the PCW that snaps across its width. But we are dealing with linen post-retting that has lost its pectin cement between the fibrils. That might explain that very pretty photograph of yours (No. 5 in the series) with scorched cellulose (micro?) fibrils that have snapped across their diameter. If enough fibrils break, that would be catastrophic where the integrity of the whole fibre was concerned, would it not? Brittle is the word that springs to mind.

    Methinks there may still be quite a bit more mileage in the “scorch hypothesis” – if only for generating new approaches for looking at Shroud image v non-image fibres. Maybe Turin’s shadowy Prof Gonella has a few more stray Shroud fibres ‘in safe keeping’ in a bottom drawer he could spare, assuming he did not give his last one to Ray Rogers for the latter’s one “spliced” fibre demolition job on the radiocarbon dating…

    PS: have just discovered that Luigi Gonella is sadly no longer with us (died 2007). This pdf describing his involvement with the TS, especially Rogers. makes interesting reading:


  18. Thibault HEIMBURGER says:

    Dear Hugh,

    Your photo above :”5) End of a single scorched fibre showing broken microfibrils – X1000″
    is very amazing.
    I don’t understand.
    It can’t be microfibrils.
    It looks like a “technical fiber”, i.e a bundle of some individual fibers that are often found in any kind of linen textile.
    Are you sure that the magnification is x1000 ?
    It seems to me impossible.


  19. Hugh Farey says:

    I have replied to Thibault be email, so that I could include more photos, but the essence is:
    Yes, Photo 5 is at X1000.
    But, I now think the plank-like blocks are actually groups of hundreds of microfibrils, possibly called mesofibrils, as illustrated in a SEM photo of a flax fibre fracture at http://www.sciencedirect.com/science/article/pii/S1359835X02000404.
    I am puzzled that my photos and the SEM photo show no sign of primary cell walls, and do not look that very fortuitous photo of a torn ‘sheathed cable’ appearance illustrated by Fanti. It’s almost as if I am using a different kind of fibre altogether – although it is certainly linen. Very curious.

  20. colinsberry says:

    Fig 7 in that link is interesting, Hugh. it’s x2000 magnification. It shows 3 levels of organization if I’m not mistaken. Overall it’s a fibre, inside of which are at least half a dozen or so fibrils, two of which are broken off and shorter than the rest, and finally one can see that the fibrils are in turn collections of exceedingly fine microfibrils. The authors themselves make the distinction between fibrils and microfibrils in their text and captions.

    Comparing that Fig 7 (an SEM picture so presumably somewhat shrunken due to dehydration) with your Fig 5, and taking your word that yours definitely is x1000, which i have never doubted, I still think you are seeing fibrils. I can understand Thibault thinking otherwise – it is a spectacular picture of fractured fibrils given it’s light microscopy with an improvised cross-polaroid feature, the like of which I have not seen before.

    I’ve used it in my current post – the last for a while – suspecting it has immense significance where the reported brittleness of Shroud image fibres is concerned. It places a huge question mark over the dogma that a scorch has to be highly superficial – restricted to the PCW – to be of relevance to the Shroud. In the light of that picture, I’d say that all bets are off…

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