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Uncle Tungsten
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p79 Many of the so-called transition elements infused their compounds with characteristic colors... Sapphires, chemically, were basically nothing but corundum, a colorless aluminum oxide, but they could take on every color in the spectrum -- with a little bit of chromium replacing some of the aluminum, they would turn ruby red; with a little titanium, a deep blue; with ferrous iron, green; with ferric iron, yellow. And with a little vanadium, the corundum began to resemble alexandrite, alternating magically between red and green -- red in incandescent light, green in day light. With certain elements, at least, the merest smattering of atoms could produce a characteristic color...
p80 There were only a handful of these "coloring" elements -- titanium, vanadium, chromium, manganese, iron, cobalt, nickel, and copper, so far as I could see, being the main ones. They were, I could not help noticing, all bunched together in terms of atomic weight -- though whether this meant anything, or was just a coincidence, I had no idea at the time. It was characteristic of all of these, I learned, that they had a number of possible valency states, unlike most other elements, which had only one. Sodium, for instance, would combine with chlorine in only one way, one atom of sodium to one of chlorine: an atom of iron could combine with two atoms of chlorine to form ferrous chloride (FeCl2) or with three atoms of chlorine to form ferric chloride (FeCl3). These two chlorides were very different in many ways, including color.
Because it had four strikingly different valencies or oxidation states, and it was easy to transform these into one another, vanadium was an ideal element to experiment with. The simplest way of reducing vanadium was to start with a test tube full of (pentavalent) ammonium vanadate in solution and add small lumps of zinc amalgam. The amalgam would immediately react, and the solution would turn from yellow to royal blue (the color of tetravalent vanadium). One could remove the amalgum at this point, or let it react further, till the solution turned green, the color of trivalent vanadium. If one waited still longer, the green would disappear and be replaced by a beautiful lilac, the color of divalent vanadium. The reverse experiment was even more beautiful, especially if one layered potassium permanganate, a deep purple layer, over the delicate lilac; this would be oxidized over a period of hours and form separate layers, one above the other, of lilac divalent vanadium on the bottom, then green trivalent vanadium, then blue tetravalent vanadium, then yellow pentavalent vanadium (and on top of this, a rich brown layer of the original permanganate, now brown because it was mixed with manganese dioxide).
p80 First mention of valency states... there's still hope.
p81 These experiences with color convinced me that there was a very intimate (if unintelligible) relation between the atomic character of many elements and the color of their compounds or minerals... And from this I got a vague feeling... that the color of these metal ions, their chemical color, was related to the specific state of their atoms as they moved from one oxidation state to another. What was it about the transition elements, in particular, that gave them their characteristic colors? Were these substances, their atoms, in some way "tuned"? (Note: [Sacks refers back to an eighteenth century mathematician, Leonhard Euler, who also speculated about color]...
The nature of radiation by which we see an opaque object does not depend on the source of light but on the vibratory motion of the very small particles {atoms} of the object's surface. These little particles are like stretched strings, tuned to a certain frequency, which vibrate in response to a similar vibration of the air even if no one plucks them. Just as the stretched string is excited by the same sound that it emits, the particles of the surface begin to vibrate in tune with the incident radiation and to emit their own waves in every direction.
David Park, in The Fire Within the Eye: A Historical Essay on the Nature and Meaning of Light, writes of Euler's theory:
I think this was the first time anyone who believed in atoms ever suggested that they have a vibrating internal structure. The atoms of Newton and Boyle are clusters of hard little balls, Euler's atoms are like musical instruments. His clairvoyant insight was rediscovered much later, and when it was, nobody remembered who had it first.
Now, I think Euler was in fact completely wrong about color, but this sounds so much like a preview of String Theory, that my mind is blown. Of course, he was thinking about atoms or molecules really, while String Theory applies to the subatomic particles that -- to the amazement of anyone in the eighteenth century -- are the components of the supposedly indivisible atoms. As similar as the language sounds, I suspect if you could (perhaps call on Mephisto to) resurrect Euler and explain to him the current understanding of these topics, rather than claiming to be a precursor of String Theory, I suspect he would be depressed that he had it all so badly wrong.)
A lot of chemistry seemed to be about heat -- sometimes a demand for heat, sometimes the production of heat. Often one needed heat to start a reaction, but then it would go by itself, sometimes with a vengeance. If one simply mixed iron filings and sulfur, nothing happened -- one could still pull out the iron filings from the mixture with a magnet. But if one started to heat the mixture, it suddenly glowed, became incandescent, and something totally new -- iron sulfide -- was created. This seemed a basic, almost primordial reaction, and I imagined that it occurred on a vast scale in the earth, where molten iron and sulfur came into contact.
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p83 I liked mixing iodine and zinc, or iodine and antimony -- no added heat was needed here -- and seeing how they heated up spontaneously, sending a cloud of purple iodine vapor above them. The reaction was more violent if one used aluminum rather than zinc or antimony. If I added two or three drops of water to the mixture, it would catch fire and burn with a violet flame, spreading fine brown iodine powder over everything.
Magnesium, like aluminum, was a metal whose paradoxes intrigued me: strong and stable enough in its massive form to be used in airplane and bridge construction, but almost terrifyingly active once oxidation, combustion, got started. One could put magnesium in cold water, and nothing would happen. If one put in in hot water, it would start to bubble hydrogen: but if one lit a length of magnesium ribbon, it would continue to burn with dazzling brilliance under the water, or even in normally flame-suffocating carbon dioxide... if one heated magnesium with sand, silicon dioxide -- and what could be more inert than sand? -- the magnesium would burn brilliantly, pulling the oxygen out of the sand, producing elemental silicon or a mixture of silicon with magnesium silicide... If one then tipped the silicide into dilute hydrochloric acid, it would react to form a spontaneously inflammable gas, hydrogen silicide, or silane -- bubbles of this would rise through the solution, forming smoke rings, and ignite with little explosions as they reached the surface.
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p84 With chemistry such as this, one was playing with fire, in the literal as well as the metaphoric sense. Huge energies, plutonic forces, were being unleashed, and I had a thrilling but precarious sense of being in control -- sometimes just. This was especially the case with the intensely exothermic reactions of aluminum and magnesium; they could be used to reduce metallic ores, or even to produce elemental silicon from sand, but a little carelessness, a miscalculation, and one had a bomb on one's hands.
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p85 Some things he mentions here that I was having a problem envisioning. Here's a gutta percha (=natural rubber) bottle.
A "carboy" is a large container, like the bottle for a water-cooler.
I'm really hoping he's going to talk about the physics of chemistry, since that's the part that interests me.
p86 ...What gave coffee its aroma? What were the essential substances in cloves, apples, roses? What gave onions and garlic and radishes their pungent smell? What, for that matter, gave rubber its peculiar odor? I especially liked the smell of hot rubber, which seemed to me to have a slightly human smell (both rubber and people, I learned later, contain odoriferous isoprene). Why did butter and milk acquire sour smells when they "went off," as they tended to do in hot weather? What gave "turps," oil of turpentine, its lovely, piney smell? ...
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p87 ...the scent of pears, I had read, could be made artificially... One had only to start with one of the alcohols -- ethyl, methyl, amyl, whatever -- and distill it with acetic acid to form the corresponding ester. I was amazed that something as simple as ethyl acetate could be responsible for the complex, delicious smell of pears, and that tiny chemical changes could transform this to other fruity scents -- change the ethyl to isoamyl, and one had the smell of ripening apples; other small modifications would give esters that smelled of bananas or apricots or pineapples or grapes. This was my first experience of the power of chemical synthesis.
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p88 My interest in smells made me wonder how we recognized and categorized odors, how the nose could instantly delineate esters from aldehydes, or recognize a category such as terpenes, as it were, at a glance... there... seemed in humans to be a chemical analyser at work at least as sophisticated as the eye or the ear. There did not seem to be any simple order, like the scale of musical tones, or the colors of the spectrum; yet the nose was quite remarkable in making categorizations that corresponded, in some way, to the basic structure of the chemical molecules. All the halogens, while different, had halogenlike smells... Most esters were fruity; alcohols -- the simplest ones, anyway -- had similar "alcoholic" smells; and aldehydes and ketones, too, had their own characteristic smells.
p89 (Errors, surprises, could certainly occur, and Uncle Dave told me how phosgene, carbonyl chloride, the terrible poison gas used in the First World War, instead of signaling its danger by a halogenlike smell, had a deceptive scent like new-mown hay. This sweet, rustic smell, redolent of the hayfields of their boyhood, was the last sensation phosgene-gassed soldiers had just before they died.)
The bad smells, the stenches, always seemed to come from compounds containing sulfur (the smells of garlic and onion were simple organic sulfides, as closely related chemically as they were botanically), and these reached their climax in the sulfyuretted alcohols, the mercaptans. The smell of skunks was due to butyl mercaptan, I read...
Thinking of all the malodorous sulfur compounds and the atrocious smell of selenium and tellurium compounds, I decided that these three elements formed an olfactory as well as a chemical category, and thought of them thereafter as the "stinkogens."
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Hydrogen selenide, I decided, was perhaps the worst smell in the world. But hydrogen telluride came close, was also a smell from hell...
This is so frustrating. He talks about the chemical origins of smells but doesn't go the next step and talk about the -- let's call it "valence" -- reason for this. He doesn't even explain the similarity of scents: Why do ripening apples smell like isoamyl acetate? Is that chemical or something similar present in the apples?
I'm glad that he seconds my observation that the sense of smell is a precise chemical process. But what's behind this at the level of physics. And how do our brains perform this chemistry?
Chapter 9 Housecalls
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p93 ...He [Oliver's doctor father] loved doing housecalls more than anything else, for they were social and sociable as well as medical, would allow him to enter a family and home, get to know everybody and their circumstances, see the whole-complexion and context of a condition. Medicine, for him, was never just diagnosing a disease, but had to be seen and understood in the context of patients' lives, the particularities of their personalities, their feelings, their reactions.
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Driving through the City, deserted on a Sunday, was a sobering experience in 1946, for the devastation wrought by the bombing was still fresh, and there had been little rebuilding as yet. This was even more evident in the East End, where a fifth of the buildings, perhaps, had been leveled. But there was still a strong Jewish community there, and restaurants and delicatessens like no where in the world. My father... had been the Yiddish-speaking doctor of the Yiddish-speaking community around... [the London Hospital in Whitechapel Road] for ten years...
I've copied this passage for two reasons; first the better practice of medicine in those simpler times; but also because there's an interesting story to the greater destruction on the East Side of London during the war. From this passage, it isn't possible to tell how much of the destruction was from the literal bombing by the Luftwaffe, and how much was the result of the V-1 and V-2 programs at the very end of the war. I have a feeling I've told this story before, but it's an interesting ethical tale so I'm going to tell it again.
MI5 had control of virtually all the German agents in Britain toward the end of WW2, so MI5 decided what reports went back to Germany. At the time of the Vengeance attacks, it was judged that the best they could do to undermine the German plan was to miss-report the landing sites of the flying or ballistic bombs so as to throw off the aim of the entire operation. The only way for this to work was to make the East End, instead of the center of London, the actual target. This worked splendidly with many bombs landing way to the east and few actually hitting the center of London -- but the East End suffered and the government continued to keep this all a secret until long after the war was over.
In the terms of The Righteous Mind discussion of morality, this was the equivalent of pushing an innocent bystander onto the tracks to stop the trolley and save more people.
There are a couple additional things in this chapter that I'm not going to copy out but do what to comment on. Sacks describes his father as a great mimic, he could mimic the "festination" of a mentor doctor, but also asthma, convulsions, and paralysis. And he speculates that this made him sensitive to the situation of his patients. I would also suspect that this was an excellent way to remember and notice certain symptoms -- using body memory as it were.
The second thing has to do with his father's brother, Bennie, who had been excommunicated from the family and never mentioned after marrying a gentile in Portugal. It wasn't until after his father's death that Oliver Sacks learned that the "fat farm" his father had been attending yearly without any success had actually been visits to his brother Bennie.
On the one hand, of course, this seems absurd. But having just read The Righteous Mind, I can also see the importance of this in preserving Jewish culture. I've skipped most of what Sacks has written to stress the importance of Judaism in his family. I don't see it as relevant to most of the topics here that interest me. But, it was essential in preserving the culture -- including intellectual and entrepreneurial culture -- which the Jewish people came to represent in the history of Europe in the past 500 and more years.
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