A brief course of exercises in physics formed part of the fourth-year chemistry program: simple measurements of viscosity, surface tension, rotatory power, and suchlike exercises. The course was conducted by a young assistant, thin, tall, a bit hunched over, polite, and extraordinarily shy, who behaved in a way that we were not used to. Our other teachers, almost without exception, showed themselves convinced of the importance and excellence of the subject they taught; some of them were in good faith, for others it was evidently a matter of personal supremacy, of their private hunting grounds. That assistant, however, almost had the air of apologizing to us, of ranging himself on our side: in his somewhat embarrassed and well-bred ironic smile, one seemed to read: “I too know that with this antiquated and worn-out equipment you’ll not be able to put together anything useful, and that furthermore these are all marginal futilities, and knowledge lives elsewhere; but this is a trade that you and I too must work at—so please try not to do much damage and to learn as much as you can.” In short, all the girls in the course fell in love with him.
During the span of those months I made desperate attempts to be taken on as a student assistant by this or that professor. Some of them snidely or even arrogantly told me that the racial laws prohibited it; others fell back on hazy or flimsy excuses. After having imperturbably collected the fourth or fifth rejection, I was going home one evening on my bike, with an almost palpable load of disheartenment and bitterness on my back. I was pedaling listlessly up Via Valperga Caluso, while from the Valentino Park gusts of freezing wind overtook and passed me; it was night by now, and the light of the street lamps, covered with purple for the blackout, did not prevail over the mist and darkness. The passersby were few and hurried; and then suddenly one among them caught my attention. He was going in my direction with a long, slow stride, he wore a long black overcoat, and his head was bare. He was walking a bit hunched over and looked like the assistant—it was the assistant. I passed him, uncertain as to what I should do; then I plucked up my courage, went back, and once again did not dare speak to him. What did I know about him? Nothing. He could be indifferent, a hypocrite, even an enemy. Then I thought that I risked nothing but another rejection, and without beating around the bush I asked him whether it would be possible to be accepted for experimental work in his school. The assistant looked at me with surprise; and instead of going into the long explanation I expected, he replied with two words from the Gospel: “Follow me.”
The inside of the Institute of Experimental Physics was full of dust and century-old ghosts. There were rows of glass-doored cupboards packed with slips of paper, yellowed and gnawed by mice and paper moths: these were the observations of eclipses, registrations of earthquakes, meteorological bulletins from well into the last century. Along the walls of one corridor I found an extraordinary trumpet, more than thirty feet long, whose origin, purpose, and use no one any longer knew—perhaps it was to announce the Day of Judgment, when all that which is hidden will appear. There was an Aeolipyle in Secession style, a Hero’s fountain, and a whole obsolete and prolix fauna of contraptions for generations destined for classroom demonstrations: a pathetic and ingenuous form of minor physics, in which stage setting counts for more than concept. It is neither illusionism nor conjuring trick but borders on them.
The assistant welcomed me in the tiny room on the ground floor where he himself lived, and which was bristling with a much different sort of equipment, unknown and exciting enthusiasm.
Some molecules are carriers of an electrical dipole; they behave in short in an electrical field like minuscule compass needles: they orient themselves, some more sluggishly, others less so. Depending on conditions, they obey certain laws with greater or less respect. Well, now, these devices served to clarify those conditions and that inadequate respect. They were waiting for someone to put them to use; he was busy with other matters (astrophysics, he specified, and the information shook me to the marrow: so I had an astrophysicist right in front of me, in flesh and blood!) and besides he had no experience with certain manipulations which were considered necessary to purify the products that had to be measured; for this a chemist was necessary, and I was the welcomed chemist. He willingly handed over the field to me and the instruments. The field was two square meters of a table and desk; the instruments, a small family, but the most important were the Westphal balance and the heterodyne. The first I already knew; with the second I soon established a friendship. In substance it was a radio-receiving apparatus, built to reveal the slightest differences in frequency; and in fact, it went howlingly out of tune and barked like a watchdog simply if the operator shifted in his chair or moved a hand, or if someone just came into the room. Besides, at certain hours of the day, it revealed a whole intricate universe of mysterious messages, Morse tickings, modulated hisses, and deformed, mangled human voices, which pronounced sentences in incomprehensible languages, or others in Italian, but they were senseless sentences, in code. It was the radiophonic Babel of the war, messages of death transmitted by ships or planes from God knows who to God knows whom, beyond the mountains and the sea.
Beyond the mountains and the sea, the assistant explained to me, there was a scholar named Onsager, about whom he knew nothing except that he had worked out an equation that claimed to describe the behavior of polar molecules under all conditions, provided that they were in a liquid state. The equation functioned well for diluted solutions; it did not appear that anyone had bothered to verify it for concentrated solutions, pure polar liquids, and mixtures of the latter. This was the work that he proposed I do, to prepare a series of complex liquids and check if they obeyed Onsager’s equation, which I accepted with indiscriminate enthusiasm. As a first step, I would have to do something he did not know how to do: at that time it was not easy to find pure products for analysis, and I was supposed to devote myself for a few weeks to purifying benzene, chlorobenzene, chlorophenols, aminophenols, toluidines, and more.
A few hours of contact were sufficient for the assistant’s personality to become clearly defined. He was thirty, was recently married, came from Trieste but was of Greek origin, knew four languages, loved music, Huxley, Ibsen, Conrad, and Thomas Mann, the last so dear to me. He also loved physics, but he was suspicious of every activity that set itself a goal: therefore, he was nobly lazy and, naturally, detested Fascism.
His relationship to physics perplexed me. He did not hesitate to harpoon my last hippogriff, confirming quite explicitly that message about “marginal futility” which we had read in his eyes in the lab. Not only those humble exercises of ours but physics as a whole was marginal, by its nature, by vocation, insofar as it set itself the task of regulating the universe of appearances, whereas the truth, the reality, the intimate essence of things and man exist elsewhere, hidden behind a veil, or seven veils (I don’t remember exactly). He was a physicist, more precisely an astrophysicist, diligent and eager but without illusions: the Truth lay beyond, inaccessible to our telescopes, accessible to the initiates. This was a long road which he was traveling with effort, wonderment, and profound joy. Physics was prose: elegant gymnastics for the mind, mirror of Creation, the key to man’s dominion over the planet; but what is the stature of Creation, of man and the planet? His road was long and he had barely started up it, but I was his disciple: Did I want to follow him?
It was a terrifying request. To be the assistant’s disciple was for me an enjoyment of every minute, a never before experienced bond, without shadows, rendered more intense by the certainty that the relationship was mutual: I, a Jew, excluded and made skeptical by recent upheavals, the enemy of violence but not yet caught up in the necessity of an opposed violence, I should be for him the ideal interlocutor, a white sheet on which any message could be inscribed.
I did not mount the new gigantic hippogriff which the assistant offered me. During those months the Germans destroyed Belgrade, broke the Greek resistance, invaded Crete from the air: that was the Truth, that was the Reality. There were no escape routes, or
not for me. Better to remain on the Earth, playing with the dipoles for lack of anything better, purify benzene and prepare for an unknown but imminent and certainly tragic future. To purify benzene, then, under the conditions to which the war and the bombings had reduced the Institute was not an insignificant undertaking: the assistant declared that I had carte blanche, I could rummage everywhere from basement to attic, appropriate any instrument or product, but I could not buy anything, even he couldn’t, it was a regime of absolute autarky.
In the basement I found a huge demijohn of technical benzene, at 95 percent purity, better than nothing, but the manuals prescribed rectifying it and then putting it through a final distillation in the presence of sodium, to free it from the last traces of humidity. To rectify means to distill by fractions, discarding the fractions that boil lower or higher than prescribed, and gathering the “heart,” which must boil at a constant temperature: I found in the inexhaustible basement the necessary glassware, including one of those Vigreux distillation columns, as pretty as a piece of lace, the product of superhuman patience and ability on the part of the glass blower, but (be it said between us) of debatable efficiency, I made the double boiler with a small aluminum pot.
Distilling is beautiful. First of all, because it is a slow, philosophic, and silent occupation, which keeps you busy but gives you time to think of other things, somewhat like riding a bike. Then, because it involves a metamorphosis from liquid to vapor (invisible), and from this once again to liquid; but in this double journey, up and down, purity is attained, an ambiguous and fascinating condition, which starts with chemistry and goes very far. And finally, when you set about distilling, you acquire the consciousness of repeating a ritual consecrated by the centuries, almost a religious act, in which from imperfect material you obtain the essence, the usia, the spirit, and in the first place alcohol, which gladdens the spirit and warms the heart. I took two good days to obtain a fraction of satisfying purity: for this operation, since I had to work with an open flame, I had voluntarily exiled myself to a small room on the second floor, deserted and empty and far from any human presence.
Now I had to distill a second time in the presence of sodium. Sodium is a degenerated metal: it is indeed a metal only in the chemical significance of the word, certainly not in that of everyday language. It is neither rigid nor elastic; rather it is soft like wax; it is not shiny or, better, it is shiny only if preserved with maniacal care, since otherwise it reacts in a few instants with air, covering itself with an ugly rough rind: with even greater rapidity it reacts with water, in which it floats (a metal that floats!), dancing frenetically and developing hydrogen. I ransacked the entrails of the Institute in vain: like Ariosto’s Astolfo on the Moon I found dozens of labeled ampules, hundreds of abstruse compounds, other vague anonymous sediments apparently untouched for generations, but not a sign of sodium. Instead I found a small phial of potassium: potassium is sodium’s twin, so I grabbed it and returned to my hermitage.
I put in the flask of benzene a lump of potassium, “as large as half a pea”—so said the manual—and diligently distilled the contents: toward the end of the operation I dutifully doused the flame, took apart the apparatus, let the small amount of liquid in the flask cool off a bit, and then with a long pointed stick skewered the “half pea” of potassium and lifted it out.
Potassium, as I said, is sodium’s twin, but it reacts with air and water with even greater energy: it is known to everyone (and was known also to me) that in contact with water it not only develops hydrogen but also ignites. So I handled my “half pea” like a holy relic: I placed it on a piece of dry filter paper, wrapped it up in it, went down into the Institute’s courtyard, dug out a tiny grave, and buried the little bedeviled corpse. I carefully tamped down the earth above it and went back up to my work.
I took the now empty flask, put it under a faucet, and turned on the water. I heard a rapid thump and from the neck of the flask came a flash of flame directed at the window that was next to the washbasin and the curtains around it caught fire. While I was stumbling around looking for some even primitive means to extinguish it, the panels of the shutter began to blister and the room was now full of smoke. I managed to push over a chair and tear down the curtains; I threw them on the floor and stomped furiously on them, while the smoke half blinded me and my blood was throbbing violently in my temples.
When it was all over, when the incandescent tatters were extinguished, I remained standing there for a few minutes, weak and stunned, my knees turned to water, contemplating the vestiges of the disaster without seeing them. As soon as I got my breath back, I went to the floor below and told the assistant what had happened. If it is true that there is no greater sorrow than to remember a happy time in a state of misery, it is just as true that calling up a moment of anguish in a tranquil mood, seated quietly at one’s desk, is a source of profound satisfaction.
The assistant listened to my account with polite attention but with a questioning look: Who had compelled me to embark on that voyage, and to distill benzene by going to so much trouble? In a way, it served me right: these are the things that happen to the profane, to those who dawdle and play before the portals of the temple instead of going inside. But he didn’t say a word; he resorted for the occasion (unwillingly, as always) to the hierarchical distance and pointed out to me that an empty flask does not catch fire: so it must not have been empty. It must have contained, if nothing else, the vapor of the benzene, besides of course the air that came in through its neck. But one has never seen the vapor of benzene, when cold, catch fire by itself: only the potassium could have set fire to the mixture, and I had taken out the potassium. All of it?
All, I answered; but then I was visited by a doubt, returned to the scene of the accident, and found fragments of the flask still on the floor: on one of them, by looking closely, one could see, barely visible, a tiny white fleck. I tested it with phenolphthalein: it was basic, it was potassium hydroxide. The guilty party had been found: adhering to the glass of the flask there must have remained a minuscule particle of potassium, all that was needed to react with the water I had poured in and set fire to the benzene vapors.
The assistant looked at me with an amused, vaguely ironic expression: better not to do than to do, better to meditate than to act, better his astrophysics, the threshold of the Unknowable, than my chemistry, a mess compounded of stenches, explosions, and small futile mysteries. I thought of another moral, more down to earth and concrete, and I believe that every militant chemist can confirm it: that one must distrust the almost-the-same (sodium is almost the same as potassium, but with sodium nothing would have happened), the practically identical, the approximate, the or-even, all surrogates, and all patchwork. The differences can be small, but they can lead to radically different consequences, like a railroad’s switch points; the chemist’s trade consists in good part in being aware of these differences, knowing them close up, and foreseeing their effects. And not only the chemist’s trade.
NICKEL
I had in a drawer an illuminated parchment on which was written in elegant characters that on Primo Levi, of the Jewish race, had been conferred a degree in Chemistry summa cum laude. It was therefore a dubious document, half glory and half derision, half absolution and half condemnation. It had remained in that drawer since July 1941, and now we were at the end of November. The world was racing to catastrophe, and around me nothing was happening. The Germans had spread like a flood in Poland, Norway, Holland, France, and Yugoslavia and had penetrated the Russian steppes like a knife cutting through butter. The United States did not move to help the English, who remained alone. I could not find work and was wearing myself out looking for any sort of paid occupation; in the next room my father, prostrated by a tumor, was living his last months.
The doorbell rang—it was a tall, thin young man wearing the uniform of the Italian army, and I immediately recognized in him the figure of the messenger, the Mercury who guides souls, or, if one wishes, the annunciato
ry angel. In short, the person for whom everyone waits, whether he knows it or not, and who brings the heavenly message that changes your life for good or ill, you don’t know which until he opens his mouth.
He opened his mouth, and he had a strong Tuscan accent and asked for Dr. Levi, who incredibly was myself (I still wasn’t accustomed to the title), introduced himself urbanely, and offered me a job. Who had sent him to me? Another Mercury, Caselli, the inflexible custodian of another man’s fame: that “laude” on my diploma had actually served for something.
That I was a Jew the lieutenant apparently knew (in any event, my last name left little room for doubt), but it didn’t seem to matter to him. Moreover, it seemed that the business somehow suited him, that he took a bitter and subtle pleasure in breaking the laws of racial separation—in short, he was secretly an ally and sought an ally in me.
The work he offered me was mysterious and quite fascinating. “In some place” there was a mine, from which was taken 2 percent of some useful material (he didn’t tell me what) and 98 percent of sterile material, which was piled up in a nearby valley. In this sterile material there was nickel; very little, but its price was so high that its recovery should be given some thought. He had an idea, in fact a cluster of ideas, but he was in the military service and had little free time. I was supposed to replace him, test his ideas in the lab, and then, if possible, together with him, realize them industrially. It was clear that; this required my transfer to that “some place,” which was then sketchily described. The transfer would take place under a double seal of secrecy. In the first place, for my protection, nobody should know my name nor my abominable origin, because the “some place” was under the control of the military authorities; and in the second place, to protect his idea, I would have to swear on my honor not to mention it to anyone. Besides, it was clear that one secret would reinforce the other and that therefore, to a certain degree, my condition as an outcast couldn’t have been more opportune.