Shiny Shoes

A look at my red shoe polish

Last week I went walking in the rain wearing my black leather shoes. Predictably, my shoes got wet. As they dried salt stains appeared, creating jagged white lines across the dull black leather. I’m not particularly fussy about my footwear, however, I want them to look well kept. So, I dug out my shoe polish tin and brush to return the shoes to their uniform black state.

As soon as I twist open the lid, the shoe polish smell takes me back to when I was in the military. Boots polished to a glossy shine was required back then - a feat that included a time-consuming regimen of spit and polish. I never really had the patience to keep my parade boots to the required shine as I always could think of better things to do. As a result, I suffered the consequence of not having shiny enough shoes more than once. I do however, have no problem brush shining my shoes to preserve the leather and keep them black.

The few moments it took to blacken my shoes started me to wondering: what is shoe polish anyway?

From wikipedia: Shoe polish is a waxy paste or cream to polish, waterproof, restore the appearance and extend the life of leather footwear. Originally concocted from wax and tallow, generally people made their own shoe polish. Tinned shoe polish took off during World War I as suddenly there were hordes of soldiers who needed to shine their shoes. Recipes for shoe polish have evolved by going into the realm of industrial chemistry. Now they are composed of a multitude of ingredients including naphtha, turpentine, dyes and gum arabic. Clearly modern shoe polish is flammable (I wonder if it would work as a fire starter in the event of an apocalypse as I have several cans in the house).

Again according to wikipedia, banana peels can be used to shine shoes - who knew? So banana peels can make my shoes shiny, what can make them black?

There is a recipe made from olive oil and lemon juice here, again lacking a blackening ingredient. A recipe more along what I would expect can be found here. These directions use: charcoal (what makes the polish black), hard soap, kerosene (still flammable), citric acid and liquid paraffin. More recipes can be found here. Since I have lots of shoe polish at the moment, I haven't tried any of these concoctions - yet.

As a tangent - I polish my black shoes with red polish (the tin calls it 'mahogany') from time to time as I like the rich colour the red adds. I always feel a little naughty doing it as I was only allowed to use black polish on my army boots.

Fireflies

Few insects vie in popular fame with the glow-worm, that curious little animal which, to celebrate the little joys of life, kindles a beacon at its tail-end. Who does not know it, at least by name? Who has not seen it roam amid the grass, like a spark fallen from the moon at its full?

- from The Insect World of J. Henri Fabre, an anthology of Jean-Henri Fabre's works translated from French by Alexander Teixeira de Mattos.

Glow-worms, also called fireflies or lightening bugs (I prefer to call them fireflies), don't live where I do, so I've never seen one. My only encounters have been in fictional accounts, but I can understand how they capture people's imagination – I'd be captivated if glowing beetles 'like a spark fallen from the moon at its full' were flying around my backyard. I suspect I'd watch them for hours, and back when I was a kid, I would have loved to catch them. According to the Smithsonian Institution's Animal; the Definitive Visual Guide to the World's Wildlife, 2000 species of fireflies exist world-wide, ranging in size from 0.5 to 3 cm. And it's no surprise that they're typically nocturnal; what would be the point of glowing if no one could see?

Their light serves different purposes through a firefly's life. As larvae, they flash to warn predators of the larvae's toxicity. As adults, each species emits their own unique set of flashes to attract mates. Males typically can fly around to find their mate, while the flightless females stay in one place and flash. A female firefly's flashing can be the downfall of a male, since some females mimic other firefly species' flashes to earn themselves a quick meal.

A firefly's light falls into the 510 – 670 nm range, corresponding to yellow, green or pale-red and contains no infrared or ultraviolet wavelengths. They produce their light purely through a chemical reaction that triggers a light-emitting pigment to flash within specialized cells in the firefly's abdomen.

Firefly populations are decreasing. Loss of habitat makes life harder for fireflies, and light pollution may be interfering with their signals. In fact, light pollution causes all sorts of havoc for critters. For fireflies finding a mate becomes more difficult, because how can they home in on a series of flashes from a potential mate while lights are flashing all around them? For other animals excess light confuses their sense of navigation, like puffins in Iceland disorientated by city lights. Children rescue the puffins and release them – which strikes me as a bit odd since puffin is considered a delicacy there. Light pollution is such an issue (probably more because it make the stars hard to see than what it does to critters) that there is an 'International Dark-Sky Association' and places designated 'dark-sky preserves'. I wonder what all the excess artificial light is doing to us?

Lots more info about fireflies can be found here.

A sappy story

Last weekend we took a jar of used turpentine to our recycling center to be disposed of. The jar's lid wasn't on perfectly, the jar tipped as I drove around a curve, and a tiny splash of turpentine spilled, filling the car with a sent reminiscent of a pile of fir branches. The smell took me back to when I was a kid exploring the forest. Fir trees are sappy – a fact I learned early while climbing them. The fir trunk has sap blisters that burst under my hands when I grabbed the branches. The sap left sticky residue on my hands, so climbing a fir tree quickly became a inferior choice compared to the maples and alders. But, something about the sap intrigued me, so I would collect it by lancing the blisters with my pocket knife and capturing the drips in a large clam shell. When I had enough, I would light the sap to see the black smoke (probably not the smartest of ideas).

The smell of turpentine started me wondering if it's made from fir sap. It didn't take much digging to learn that what I'm calling sap is actually resin, a hydrocarbon secreted by predominantly coniferous trees and a few other plants (both the biblical frankincense and myrrh are resins). Resin is also known as pitch and it has some neat properties. It behaves as a solid normally, but if a force is imposed on it long enough the deformation will increase indefinitely, just like a liquid. Cool, but how does it become turpentine?

Resin is converted to turpentine by distillation, a process where the parts of a liquid are separated using heat – for example if you want to make a fortified wine like brandy, you would need to heat the wine and collect the alcohol as it evaporated away. Generally, turpentine is made from pine trees, but it's also a byproduct from reducing coniferous trees to pulp.

Turpentine is commonly used as a solvent; we use it for cleaning brushes coated in oil paints. It could also be used to thin out oil paints.

As a tangent, I pulled out an old country skills handbook to see what they suggested one could do with turpentine. Apparently, it was used as an ingredient in mosquito repellent along with some other nasty stuff – I was relieved to see that this concoction was to be used by saturating cloth with it and placing it by the door instead of putting in on your skin.

Good stripes, bad stripes

Stripes have been viewed in a variety of ways through time. I would have thought that as soon as people invented the loom, stripes would have followed. Stripes must be one of the easiest patterns to make – yet medieval western Europe shunned them.

Stripped clothing was considered at best demeaning and at worst downright diabolical. On the other hand, dots, discs, stars, rings and other simple repeating patterns were good – even viewed as expressing something majestic. This distinction between good and bad patterns was even applied to the animal world; horses were good and zebras were bad. Fortunately, our views about stripes has morphed with time and I can sleep in striped pajamas without worrying about my soul.

Although stripes can't tell us anything about the wearer's moral character, they can tell you what something is made of – even from a distance. Here is a rough idea how it is done (yes it's another optical trick).

Remember Newton's classic experiment where he shone light through a prism and got a rainbow coloured spectrum? If you look really, really closely at the spectrum you can see hundreds of irregularly spaced, thin, dark stripes, which is exactly what the German scientist, Joseph von Fraunhofer, did in 1814. Today, we know more than 30,000 of these lines exist in the sun's spectrum – but what are they?

Elements, like oxygen, helium and the others on the periodic table, are fundamental. They can't be broken down into smaller parts without taking extreme measures like using a super-colliders. If you shine a light (assuming this light gives off a perfectly continuous spectrum) through a gas of an element, then let the light go through a prism the resulting rainbow will have dark stripes in it. These stripes are called absorption lines and are unique to the element. So the stripes from helium will look different that the stripes from nitrogen. This means that, an element can be identified from its stripes alone.

So all those stripes in the spectrum of the sun tell us what the sun is made of – without having to go there.

References:
Universe, 5th edition by William Kaufmann and Roger Freedman, W.H. Freeman and Company, New York, 2000.
The Devil's Cloth: a history of stripes and striped fabric, by Michel Pastoureau, Columbia University Press, 1991

Bloody colours

To a bloody war and sickly season - the traditional Thursday toast of the British Navy.

Since I've already written about blue (here and here), a friend suggested I write a post on redder colours, specifically ones named after bloody battles. I only found two: magenta and solferino – both are purplish red colours, perhaps even the same colour. Magenta and Solferino are both towns in Northern Italy that were caught up in the second Italian war of Independence at the same time synthetic dyes were being made from coal tar for the first time. Magenta as a colour name is still in common use, while Solferino was the more important battle. A witness to the battle of Solferino, Henry Dunant, found it so horrible he began a campaign that ultimately resulted in the founding of the Red Cross.

In 1859, Emmanuel Verguin's experiments with aniline dyes (ie the ones from coal tar) resulted in a rich crimson red. He called the colour fuchsine after the fuchsia flower and it was an instant hit. This was a prominent colour of the uniforms at both the battle of Magenta and Solferino, both in June 1859, so I don't know if the colour took these names because of the uniforms or the bloodiness of the battlefields (I've found references both ways). A few years later, the colour's name was once more changed, this time to rosaniline, but magenta is the name that stuck. A arsenic acid oxidation process was required to make this dye causing some of its wearers to be poisoned – leaving magenta even more bloody. (For more details of synthetic dyes 'Mauve' by Simon Garfield is a good read)

If you took a good look at the colour spectrum of light, magenta wouldn't be found. Magenta is considered an extra-spectral colour because it cannot be generated by a single wavelength of light. It is formed in our minds when there are equal parts of blue and red light (in truth colours only exist because our brains perceive them).

Nylon

Way back when I took first year chemistry I found the labs to be great fun. In one lab we made our own nylon. Now, actually wearing nylons is something I despise, one step down the slippery slope to high-heels (I'm 5'10”, I don't need to be taller) and caking my face with excessive make-up, not to mention an exponential requirement for more hairspray. It's probably obvious I'm not a girly-girl, nor ever plan on becoming one (if you are a girly-girl, go ahead and be girly, I'm not judging, it's just not my thing). But, making nylon intrigues me as I'm always interested in how things are made.

The invention of Nylon is credited to Wallace Carothers in 1935 at the DuPont Experimental Station. In 1930, Carothers with the folks at DuPont had their first success with what would be eventually called neoprene – the first synthetic rubber. Carothers and his team went on to tackle the creation what would become nylon. Unfortunately, Carothers tended to bouts of depression and alcoholism, and his actual contribution to the development of nylon probably wasn't significant. Instead his coworkers did the work and credited him. In 1937, Carothers committed suicide.

Nylon was the first synthetic fiber, in a 22 September 1938 New York Times article nylon was touted to be 'stronger than steel, fine as a spider's web, more elastic than any of the common natural fibers'. Once it was announced nylon could be knitted in to stockings that were better than silk people got excited. Ironically, the first commercial application turned out to be a nylon-bristled toothbrush. Nylon stockings were said to be indestructible (I've worn nylons enough times to know that isn't true). Today nylon fibers are the second most used synthetic fiber and can be found in all sorts of things like: fabrics, carpets, musical instrument strings and ropes. The down side to nylon is that in a fire it breaks down into nasty stuff like hazardous smoke and toxic fumes. Most nylon ends slowly decaying in landfill as recycling for it isn't widely implemented.

According to Wikipedia to make nylon, molecules with an acid group on each end are reacted with molecules containing an amine group on each end. They react and form long polymer chains – and that's is what nylon is, just a trade name for a synthetic polymers.

On to how we made nylon fiber in my first year lab. I poured one liquid very carefully over a the back of a metal spoon into a glass jug so it sat on top of another liquid without excess mixing. I had forgotten what the chemicals were, but a quick internet search gave me hexanedioxyl dichloride and diaminohexane. After a minute or so a layer formed between the two chemicals. With some tongs, I pulled out the interface, which had changed to nylon. As I pulled the two liquids would form new nylon when ever they came in contact with each other and I ended up with a long string of nylon. So, from the boundary between two liquids came a length of nylon thread.

Cadmium

I was working out of my office yesterday, in a building that is basically a line of industrial workshops. I was doing some necessary but messy work and when I was done I swept out my workspace. The floor was dusty and by sweeping I put that dust into the air and no doubt breathed some of it in. It turns out that in one of the workshops at the end of the building is contaminated with cadmium. I doubt that sweeping the floor at the other end of the building exposed me to much, but I have worked with cadmium paints in the past so I did some looking into its toxicity.

Discovered in the 1800's, cadmium is a metal that has a bluish-silver look to it. It is soft and easily manipulated and can be a byproduct of zinc production. Since our bodies have no use for this metal, it is toxic to us even at low concentrations. To me the scariest part is that cadmium bioaccumulates – there has been reports of cadmium poisoning from crops downstream of mines. Ingesting it over a long period of time can result in kidney disease and various types of cancer – but inhaling cadmium fumes can be fatal relatively quickly.

Even with its scary side, cadmium is interesting stuff. I first encountered cadmium as a pigment component; it makes brightly coloured yellows, oranges and reds that last for centuries without losing their original bright hue. These shades replaced older, not light-fast pigments such as vermilion (mercury sulfide). Cadmium has also been used as a corrosion-resistant coating for steel and as a stabilizing compound in plastics.

Because of its toxicity, cadmium use is in decline. There are now non-toxic replacements for the cadmium pigments, it has been phased out of plastics and many of its other uses. Currently, most of the cadmium produced goes into nickel-cadmium batteries, which leaves a worry of how these batteries are disposed of.