To dye for

The history of dyes is actually way more interesting than it sounds.

People have been coloring cloth (and pottery, and cave walls, and their own bodies) for a very long time, but all colors don't turn out to be equally accessible to the palette.  Red, for example, is fairly easy, especially if you don't care if it's not screaming scarlet and has a slight brownish tint (what we'd call "brick red"), because that's the color of iron oxide, better known as rust.  Iron oxide is plentiful, and I know from messing around with pottery glazes that it's got two properties: (1) mixed with other minerals and/or heated in the absence of oxygen, it can give you a variety of other colors, from black to dark blue to green; and (2) it sticks to everything.  I have brushes I use in the glazing process that I used once or twice to apply an iron-based glaze, and now they're permanently stained red.

Other colors, however, aren't so easy.  Some of the more notoriously difficult ones are true blues and purples; our appending the word "royal" to royal blue and royal purple is an indicator of the fact that back then, only the really rich could afford blue or purple-dyed cloth.  Blue can be achieved using small amounts of cobalt, or finely powdered lapis lazuli, but neither is common and although they have other uses (cobalt in pottery pigments, lapis in paints) neither works well for dyeing cloth.  Lapis, in fact, was used to produce the finest rich blue pigment for oil paints, which got named ultramarine because the mineral was imported from what is now Afghanistan -- a place that was ultramarinus ("beyond the sea") to the people in Italy and France who were using it.

But dyeing cloth was another matter.  One solution was, bizarrely enough, a secretion of a sea snail of the genus Murex.  These snails' hypobranchial glands produce a gunk that when purified produces a rich purple dye that is "color fast" on cloth.

How anyone thought of doing this is an open question.  Maybe they just smeared slime from various animals on cloth until they found one that worked, I dunno.

Be that as it may, the color of the dye was called φοῖνιξ (phoinix) by the ancient Greeks, and the sea traders who cornered the market on producing and selling the dye were called the Φοίνικες (Phoinikhes).  We anglicized the word to Phoenicians -- so Phoenician means, literally, "people of the purple."

The reason all of this colorful stuff comes up is a paper in Science Advances that describes how a group of chemists in Portugal successfully determined the origin of a purple to blue (depending on how it's prepared) watercolor pigment called folium that was used in medieval watercolors.  It is a gorgeous color, but all previous attempts either to replicate it or to determine its source had been unsuccessful.  The difficulty with trying to figure out things like this is that there was no standardized naming system for plants (or anything else) back then, so the name in one place could (and probably did) vary from the name in another place.  Reading manuscripts about natural dyes from that time period, about all we can figure out is "it's made by boiling this plant we found" or "it's made from special snail slime," which doesn't really tell us much in the way of details.

Samples of medieval folium on cloth [Image courtesy of Paula Nabais/NOVA University]

In the case of folium, it was known that it came from a weedy plant of some sort, but there was no certainty about which plant it was or where it grew.  But now some Portuguese chemists have identified the source of folium as the seedpods of a roadside weed in the genus Chrozophora, a little unassuming plant in the Euphorbia family that likes dry, sunny, rocky hillsides, and when you grind up the seedpods, creates a knock-your-socks-off purple dye.  The dye was then applied to cloth, and you took small bits of the cloth and soaked them in water when you were ready to use them to make a natural watercolor paint.

The scientists were able to determine the chemical structure of the dye itself, which is pretty astonishing.  But even finding the plant was a remarkable accomplishment.  "We found it, guided by biologist Adelaide Clemente, in a very beautiful territory in Portugal [called] Granja, near a very beautiful small town Monsaraz -- a magical place, still preserved in time," said study co-author Maria João Melo, in an interview with CNN.  "Nobody in the small village of Granja knew [anything] about this little plant.  It may look like a weed, yet it is so elegant with its silvery stellate hairs that combine so well with the greyish green, and what a story there is behind it."

I'm always impressed with how intrepid our forebears were at using the resources around them to their fullest, but as with the snail slime, I'm mystified as to where that knowledge came from.  Some of it was probably by happy accident -- I think fermented milk products like yogurt and cheese probably were discovered because of milk that spoiled in just the right way, for example.  But bread has always mystified me.  Who first thought, "Let's take these seeds, and grind 'em up, and add this fungus powder to it with water until it gets all bubbly and smells funny, then stick it in the fire!  That'll be delicious with jam spread on it!"

And here -- grinding up the seedpods of a random weed ended up producing one of the rarest and prettiest dyes ever discovered.  Undoubtedly the brainstorm of some medieval artist or botanist (or both) who happened to get lucky.  Makes you wonder what other plants are out there that could have odd artistic, medicinal, or culinary uses -- especially in places of enormous biodiversity like the Amazonian rainforest, where there are probably as many plant species that have not been identified as there are ones that have been.

So if you needed another good reason to preserve biodiversity, there it is.

****************************************

Through a glass, darkly

I was chatting with my younger son a couple of days ago.  He's a professional scientific glassblower, so anything having to do with the properties, chemistry, or uses of glass is going to interest him automatically.  And this was how he ran into the name of Walter John Kilner.

My son asked me if I'd ever heard of him, which I hadn't, and he suggested I look into him as a possible topic for Skeptophilia.  What I found out was pretty interesting -- straddling that gap between "fascinating" and "crazy."

Kilner, who lived from 1847 to 1920, studied medicine, physics, and engineering at Cambridge University, eventually earning a master's degree as well as a doctorate in medicine.  He had a private medical practice as well as being a "medical electrician" -- then a brand-new field -- at St. Thomas Hospital in London.

So the man was certainly not lacking in brains.  But he veered off into an area that is fringe-y at best, and to this day we don't know if what he was seeing was real.

The basic idea is familiar to us today as the "aura," but what most people mean by that -- some sort of spiritual halo around humans (and supposedly, all living things) that conveniently can't be measured by any known technique -- is several shades more woo-woo than what Kilner meant.  He seems to have latched onto the idea of there being a kind of electromagnetic radiation given off by the human body that was outside the range of human vision, and which could potentially be used as a diagnostic tool if a device was developed that allowed us to see it.

In fact, there is invisible radiation coming from our bodies; it's infrared light, which is light that has a longer wavelength than red light.  (Nota bene: it took me some pondering to get past the misunderstanding that infrared and thermal radiation aren't the same thing.  Thermal radiation can be in any region of the spectrum -- think of the red light given off by a hot stove burner.  The wavelength of thermal radiation is dependent upon the temperature of the source.  Infrared, which can be emitted thermally, is defined by having wavelengths longer than that of visible light, regardless of how it's generated.)

More germane to Kilner and his goggles, although the human eye can't detect it, mosquitoes' eyes can (one of the ways they find us in the dark), and it can be sensed by the "loreal pits" of pit vipers that they use for finding prey at night, not to mention the infrared goggles used by the military, which convert long-wavelength infrared light to shorter wavelengths that we can see.  

So there was at least some scientific basis for what he proposed, and remember that this would have been in the late nineteenth century, when the properties of electromagnetic radiation were still largely mysterious.  What Kilner proposed was that since light is altered when it passes through filters of any kind, there might be a filter that could take the electromagnetic radiation from the aura and convert it to visible light.

His approach was to take thin layers of alcohol-soluble dyes, most derived from coal tar, sandwiched between two sheets of clear glass.  He claimed he found one that worked -- a blue dye he called dicyanin -- but according to Kilner, it was difficult to produce, so he started fishing around for a substitute.

Along the way, he convinced a lot of people that his dicyanin filter allowed him to see the human aura, and generated a huge amount of enthusiasm.  People suggested other blue dyes -- cobalt-based ones, and other coal tar derivatives like pinacyanol -- but the results he obtained were equivocal at best.  Nobody was able to produce dicyanin again, or even figure out what its chemical composition was, which certainly made any skeptics raise an eyebrow.  But to the end of his life, Kilner swore that his dicyanin filter allowed him to see clearly an aura around his volunteers' naked bodies, despite an analysis by the British Medical Journal stating bluntly, "Dr. Kilner has failed to convince us that his 'aura' is more real than Macbeth's visionary dagger."

So what, if anything, did Kilner see?  The easiest answer is: we don't know.

The whole thing reminds me of Kirlian photography -- those familiar (and striking) photographs that result from placing a photographic plate on top of a high voltage source, then adding a flat object of some kind.  This produces a coronal discharge, a purely physical effect caused by the voltage creating temporary ionization of the air molecules.  Pretty much anything works; I've seen Kirlian photographs of coins.  But this doesn't stop the woo-woos from claiming that Kirlian photographs are capturing the aura, and giving it all sorts of spiritual and/or esoteric overtones.

Kirlian photograph of a dusty miller leaf [Image licensed under the Creative Commons Rarobison11, MDR Dusty Miller, CC BY-SA 4.0]

In the case of Kilner, though, the effect was never successfully replicated.  This hasn't stopped people from making "Kilner goggles" that you can still buy online, if you've got no better use for your money.  But as far as Kilner himself, he seems to have been entirely sincere -- i.e., not a charlatan or outright liar.  He pretty clearly believed he'd seen something that deserved an explanation.  Whether it was some kind of optical effect produced by his mysterious dicyanin, or a faint blur in the image that he then gave more significance than it deserved, we honestly don't know.  (This is reminiscent of the "canals of Mars," first described by astronomer Giovanni Schiaparelli, which were clearly an artifact of poor telescope quality -- when the optical equipment improved, the Martian canals mysteriously vanished, never to be seen again.)

Another possibility, though, was brought up by my wife; a lot of the dyes and solvents that Kilner used are neurotoxic.  It could be that what he was seeing was a visual disturbance caused by inhaling the fumes from nasty compounds like polycyclic aromatic hydrocarbons, common in the coal tar he was using to prepare his dyes.

The interesting thing is that Kilner completely dismissed the esoteric spin that auras were given during the last decade of his life, primarily by the Theosophists and Spiritualists who were skyrocketing in membership during the first decades of the twentieth century.  Kilner remained to the end a staunch believer in the scientific method, and that anything he'd seen had a purely physical origin that was explainable in terms of the properties of light and electromagnetism.

It's an interesting case.  The fact that in the hundred years since he died, no one's ever been able to replicate his findings, strongly supports the fact that he was simply wrong -- he'd seen something, but it had nothing to do with anything that could be called an aura.  Even so, he's an interesting example of someone who was clearly trying to do things the right way, but his own determination to prove his conjecture blinded him to the obvious conclusion.

Further stressing the truth of Leonardo da Vinci's statement that "We must doubt the certainty of everything that passes through our senses."

*************************************

One of the most devastating psychological diagnoses is schizophrenia.  United by the common characteristic of "loss of touch with reality," this phrase belies how horrible the various kinds of schizophrenia are, both for the sufferers and their families.  Immersed in a pseudo-reality where the voices, hallucinations, and perceptions created by their minds seem as vivid as the actual reality around them, schizophrenics live in a terrifying world where they literally can't tell their own imaginings from what they're really seeing and hearing.

The origins of schizophrenia are still poorly understood, and largely because of a lack of knowledge of its causes, treatment and prognosis are iffy at best.  But much of what we know about this horrible disorder comes from families where it seems to be common -- where, apparently, there is a genetic predisposition for the psychosis that is schizophrenia's most frightening characteristic.

One of the first studies of this kind was of the Galvin family of Colorado, who had ten children born between 1945 and 1965 of whom six eventually were diagnosed as schizophrenic.  This tragic situation is the subject of the riveting book Hidden Valley Road: Inside the Mind of an American Family, by Robert Kolker.  Kolker looks at the study done by the National Institute of Health of the Galvin family, which provided the first insight into the genetic basis of schizophrenia, but along the way gives us a touching and compassionate view of a family devastated by this mysterious disease.  It's brilliant reading, and leaves you with a greater understanding of the impact of psychiatric illness -- and hope for a future where this diagnosis has better options for treatment.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

 

To dye for

The history of dyes is actually way more interesting than it sounds.

People have been coloring cloth (and pottery, and cave walls, and their own bodies) for a very long time, but all colors don't turn out to be equally accessible to the palette.  Red, for example, is fairly easy, especially if you don't care if it's not screaming scarlet and has a slight brownish tint (what we'd call "brick red"), because that's the color of iron oxide, better known as rust.  Iron oxide is plentiful, and I know from messing around with pottery glazes that it's got two properties: (1) mixed with other minerals and/or heated in the absence of oxygen, it can give you a variety of other colors, from black to dark blue to green; and (2) it sticks to everything.  I have brushes I use in the glazing process that I used once or twice to apply an iron-based glaze, and now they're permanently stained red.

Other colors, however, aren't so easy.  Some of the more notoriously difficult ones are true blues and purples; our appending the word "royal" to royal blue and royal purple is an indicator of the fact that back then, only the really rich could afford blue or purple-dyed cloth.  Blue can be achieved using small amounts of cobalt, or finely powdered lapis lazuli, but neither is common and although they have other uses (cobalt in pottery pigments, lapis in paints) neither works well for dyeing cloth.  Lapis, in fact, was used to produce the finest rich blue pigment for oil paints, which got named ultramarine because the mineral was imported from what is now Afghanistan -- a place that was ultramarinus ("beyond the sea") to the people in Italy and France who were using it.

But dyeing cloth was another matter.  One solution was, bizarrely enough, a secretion of a sea snail of the genus Murex.  These snails' hypobranchial glands produce a gunk that when purified produces a rich purple dye that is "color fast" on cloth.

How anyone thought of doing this is an open question.  Maybe they just smeared slime from various animals on cloth until they found one that worked, I dunno.

Be that as it may, the color of the dye was called φοῖνιξ (phoinix) by the ancient Greeks, and the sea traders who cornered the market on producing and selling the dye were called the Φοίνικες (Phoinikhes).  We anglicized the word to Phoenicians -- so Phoenician means, literally, "people of the purple."

The reason all of this colorful stuff comes up is a paper in Science Advances last week that a group of chemists in Portugal have successfully determined the origin of a purple to blue (depending on how it's prepared) watercolor pigment called folium that was used in medieval watercolors.  It is a gorgeous color, but all previous attempts either to replicate it or to determine its source had been unsuccessful.  The difficulty with trying to figure out things like this is that there was no standardized naming system for plants (or anything else) back then, so the name in one place could (and probably did) vary from the name in another place.  Reading manuscripts about natural dyes from that time period, about all we can figure out is "it's made by boiling this plant we found" or "it's made from special snail slime," which doesn't really tell us much in the way of details.

Samples of medieval folium on cloth [Image courtesy of Paula Nabais/NOVA University]

In the case of folium, it was known that it came from a weedy plant of some sort, but there was no certainty about which plant it was or where it grew.  But now some Portuguese chemists have identified the source of folium as the seedpods of a roadside weed in the genus Chrozophora, a little unassuming plant in the Euphorbia family that likes dry, sunny, rocky hillsides, and when you grind up the seedpods, creates a knock-your-socks-off purple dye.  The dye was then applied to cloth, and you took small bits of the cloth and soaked them in water when you were ready to use them to make a natural watercolor paint.

The scientists were able to determine the chemical structure of the dye itself, which is pretty astonishing.  But even finding the plant was a remarkable accomplishment.  "We found it, guided by biologist Adelaide Clemente, in a very beautiful territory in Portugal [called] Granja, near a very beautiful small town Monsaraz -- a magical place, still preserved in time," said study co-author Maria João Melo, in an interview with CNN.  "Nobody in the small village of Granja knew [anything] about this little plant.  It may look like a weed, yet it is so elegant with its silvery stellate hairs that combine so well with the greyish green, and what a story there is behind it."

I'm always impressed with how intrepid our forebears were at using the resources around them to their fullest, but as with the snail slime, I'm mystified as to how some of it came about.  Some of it was probably by happy accident -- I think fermented milk products like yogurt and cheese probably were discovered because of milk that spoiled in just the right way, for example.  But bread has always mystified me.  Who first thought, "Let's take these seeds, and grind 'em up, and add this fungus powder to it with water until it gets all bubbly and smells funny, then stick it in the fire!  That'll be delicious with jam spread on it!"

And here -- grinding up the seedpods of a random weed ended up producing one of the rarest and prettiest dyes ever discovered.  Undoubtedly the brainstorm of some medieval artist or botanist (or both) who happened to get lucky.  Makes you wonder what other plants are out there that could have odd artistic, medicinal, or culinary uses -- especially in places of enormous biodiversity like the Amazonian rainforest, where there are probably as many plant species that have not been identified as there are ones that have been.

So if you needed another good reason to preserve biodiversity, there it is.

*****************************

Finding a person who is both an expert in an arcane field like quantum physics, and is also able to write lucidly about it for the interested layperson, is rare indeed.  Such a person is Sean Carroll, whose books From Eternity to Here, The Particle at the End of the Universe, and The Big Picture explore such ideas as the Big Bang, the Higgs boson, and what exactly time is -- and why it seems to flow in only one direction.

In his latest book, Something Deeply Hidden, Carroll looks not only at the non-intuitive world of quantum physics, but at the problem at the heart of it -- the "collapse of the wave function," how a reality that is a field of probabilities (experimental data agrees with quantum theory to an astonishing degree on this point) somehow converts to a reality with definitive outcomes when it's observed.  None of the solutions thus proposed, Carroll claims, are really satisfying -- so physicists are left with a dilemma, a theory that has been experimentally verified to a fare-thee-well but still has a giant gaping unexplained hole at its center.

Something Deeply Hidden is an amazing read, and will fascinate you from page 1 until you close the back cover.  It will also repeatedly blow your mind in its description of a universe that doesn't behave at all like what common sense says it should.  And Sean Carroll is exactly the author to navigate these shark-infested waters.  This is a book you don't want to miss.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]