Sunday, March 13, 2016

149. Uncle Tungsten - II. Scheele


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Uncle Tungsten

Chapter 4 "An Ideal Metal"

p32 [This first passage is here simply as a shout out to the opening chapter of Thomas Pynchon's Gravity's Rainbow] I returned to London in the summer of 1943, after four years of exile, a ten-year-old boy, withdrawn and disturbed in some ways, but with a passion for metals, for plants, and for numbers. Life was beginning to resume some degree of normality... 

One sign of this, for me, was the fact that my father was given, through a series of intermediaries, an unheard-of thing, a banana from North Africa. None of us had seen a banana since the start of the war, and so my father divided in, sacramentally, into seven equal segments: one each for my mother and himself, one for Auntie Birdie, and one apiece for my brothers and myself. The tiny segment was placed, like a Host, on the tongue, then savored slowly as it was swallowed. Its taste was voluptuous, almost ecstatic, at once a reminder and symbol of times past and an anticipation of times to come, an earnest, a token, perhaps, that I had come home to stay.

[Before the war the Sacks household had employed 6 servants but none returned after the war.]

p41 "Nature offers you copper and silver and gold native, as pure metals," Uncle [Dave or Tungsten] would say, "and in South America and the Urals, she offers the platinum metals, too." ...

But most metals occurred in the form of oxides, or "earths." Earths, he said, were sometimes called calxes, [see oxides] and these ores were known to be insoluable, incombustible, infusible, and to be, as one eighteenth-century chemist wrote, "destitute of metallic splendour." And yet, it was realized, they were very close to metals and could indeed be converted into metals if heated with charcoal; while pure metals became calxes if heated in air. What actually occurred in these processes, however, was not understood. There can be a deep practical knowledge, Uncle said, long before theory: it was appreciated, in practical terms, how one could smelt ores and make metals, even if there was no correct understanding of what actually went on.
...
We know now, he went on, that when one heats the oxides with charcoal, the carbon in the charcoal combines with their oxygen and in this way "reduces" them, leaving the pure metal. [what confuses me about this terminology is that the "reducer" is reduced by an electron, thus becoming "oxidized", while the "oxidizer" gains an electron, and thus is "reduced."] Without the ability to reduce metals from their oxides, he would say, we would never have known any metals other than the handful of native ones. There would never have been a bronze age much less an iron age; there would never have been the fascinating discoveries of the eighteenth-century, when a dozen and a half new metals (including tungsten!) were extracted from their ores.

p42 Uncle Dave showed me some pure tungstic oxide... I took the bottle from him; it contained a dense yellow powder that was surprisingly heavy, almost as heavy as iron. "All we need to do," he said, "is heat it with some carbon in a crucible until it's red hot." He mixed the yellow oxide and the carbon together, and put the crucible in a corner of the huge furnace. A few minutes later, he withdrew it with long tongs, and as it cooled, I was able to see... The carbon was all gone, as was most of the yellow powder, and in their place were grains of dully shinning grey metal...

"There's another way we could make it," Uncle said. "It's more spectacular." He mixed the tungstic oxide with finely powdered aluminum, and then placed some sugar, some potassium perchlorate, and a little sulfuric acid ["The historical name of this acid is oil of vitriol."] on top. The sugar and perchlorate and acid took fire at once, and this in turn ignited the aluminum and tungstic oxide, which burned furiously, sending up a shower of brilliant sparks. When the sparks cleared, I saw a white-hot globule of tungsten in the crucible. "That is one of the most violent reactions there is," said Uncle. "They call this the thermite process; you can see why. It can generate a temperature of three thousand degrees or more -- enough to melt tungsten...

What's notable here is that in the first process energy had to be added in the form of heat. In the second process, the combination of substances provided the energy needed to generate the heat.

Also important to note, tungsten was first discovered in the 1780s, before Goethe finished part 1 of Faust. While I don't recall any of our commentators on that work talking about the impact chemical breakthroughs of the time may have had on Goethe, I'm sure he was aware of this and that this is what Mephisto was getting at when he was talking about the wealth concealed in the earth that he was going to help Faust retrieve for the Emperor. 


p44 [Carl Wilhelm] Scheele was one of uncle Dave's great heroes. Not only had  he discovered tungstic acid and molybdic acid (from which the new element molybdenum was made), but hydrofluoric acid, hydrogen sulfide, arsine, and prussic acid, and a dozen organic acids, too. [If you follow those links you will be amazed by the dark side of these early discoveries of science. The last -- Hydrogen cyanide leading to Zyklon B is a prime example.] All this, Uncle Dave said, he did by himself, with no assistants, no funds, no university position or salary, but working alone, trying to make ends meet as an apothecary [like Serenus Zeitblom's father in Doctor Faustus] in a small provincial Swedish town. He had discovered oxygen, not by a fluke, but by making it in several different ways; he had discovered chlorine; and he had pointed the way to the discovery of manganese, of barium, of a dozen other things. 

And Scheele died at only 44. If reducers are eager to lose an electron and oxidizers are eager to gain one, then "acids" are the sluts of chemistry as they are keen to lose an entire proton while "bases" are just waiting to receive that proton to neutralize into a "salt."

Scheele, Uncle Dave would say, was wholly dedicated to his work, caring nothing for fame or money and sharing his knowledge, whatever he had, with anyone and everyone...

Scheele, it was said, never forgot anything if it had to to with chemistry. He never forgot the look, the feel, the smell of a substance, or the way it was transformed in chemical reactions, never forgot anything he read, or was told, about the phenomena of chemistry. He seemed indifferent, or inattentive to most things else, being wholly dedicated to his single passion, chemistry. It was this pure and passionate absorption in phenomena -- noticing everything, forgetting nothing -- that constituted Scheele's special strength.

Scheele epitomized for me the romance of science. There seemed to me an integrity, an essential goodness, about a life in science, a lifelong love affair... I wanted to be a chemist. A chemist like Scheele, an eighteenth-century chemist coming fresh to the field, looking at the whole undiscovered world of natural substances and minerals, analyzing them, plumbing their secrets, finding the wonder of unknown and new metals.

Another way of structuring this book would have been by the great figures, like Scheele, who discovered our scientific world in much the same way a previous generation of explorers had discovered the true map of the earth. In which case this would have followed chapters about Alchemy, perhaps titled "Paracelsus," and Boyle and a few others. 

The alchemists will be mentioned in later chapters as a way of indicating the ignorance of the age. If you don't know what elements are or what makes them different -- and no one did at that point -- you can't understand why elements can't be transmuted into each other. Without a scientific understanding, it is all magic. 

But the reason we start instead with Scheele, I believe, is that it is this passion for chemistry that appeals to the young Oliver Sacks, and that we will later -- in the book, if not so much here -- see him personify. It is this single mindedness and turning away from the non-scientific world that appeals to him at this time.  


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