by Primo Levi
I gulped, but anyway said that I would see: alloxan is not a very common compound or very well-known, and it didn’t seem to me that my old organic chemistry book devoted more than five lines to it; at that moment I vaguely recalled only that it was a derivative of urea and had something to do with uric acid.
As soon as possible I went to the library: I mean, to the venerable library of the Chemistry Institute of the University of Turin, which at that time was as impenetrable to infidels as Mecca, and scarcely penetrable even to the faithful, like me. You might think that the administration was following the sage principle according to which it’s a good thing to discourage the arts and sciences: only one who was driven by absolute need, or by overwhelming passion, would willingly undergo the trials of self-denial that were required to consult the volumes. The hours were brief and irrational; the illumination scant; the indexes in disarray; in winter no heat; no chairs but, rather, uncomfortable, noisy metal stools; and, finally, the librarian was an insolent, incompetent, brazenly ugly boor, placed at the threshold to frighten with his look and his bark those who claimed entrance. I gained admission, overcame the trials, and hastened first to refresh my memory about the composition and structure of alloxan. Here is its portrait:
where O is oxygen, C carbon, H hydrogen (hydrogenium) and N nitrogen (nitrogenium). It’s a graceful structure, isn’t it? It makes you think of something solid, stable, well connected. In fact, in chemistry, too, as in architecture, “beautiful” buildings, that is, symmetrical and simple, are also the most solid: molecules are like the dome of a cathedral or the arches of a bridge. And it may be that the explanation is not so remote or metaphysical: to say “beautiful” is to say “desirable,” and ever since man began building, he has desired to build with the least expense and for the longest duration, and the aesthetic enjoyment that he feels in contemplating his works comes later. Certainly it hasn’t always been like this: there have been centuries when beauty was identified with decoration, overlay, embellishment; but those were probably deviant epochs, and true beauty, the beauty in which every age recognizes itself, is that of upright stones, ships’ hulls, the blade of an ax, and the wing of an airplane.
Now that the structural virtue of alloxan has been acknowledged and admired, it’s high time for you, young chemist, so fond of digressions, to get back on track: to fornicate with the material in order to earn your living, and not just yours anymore. I respectfully opened the bookcases that held the Zentralblatt and began to consult it, year by year. Hats off to the Chemisches Zentralblatt: it’s the Review of Reviews, which, ever since chemistry existed, has reported, in the form of an angrily concise abstract, everything published on a chemical subject in every review in the world. The first years are thin volumes of three or four hundred pages; today, fourteen volumes, of thirteen hundred pages each, are served up annually. It is accompanied by one majestic index of authors, one of subjects, and one of formulas, and there you can find venerable fossils, such as the legendary records in which our father Wöhler narrates the first organic synthesis, or Sainte-Claire Deville describes the first isolation of metallic aluminum.
From the Zentralblatt I was bounced to Beilstein, an equally monumental, continually updated encyclopedia in which, as in a registry office, every new compound is described, along with the methods for its preparation. Alloxan had been known for almost seventy years, but as a laboratory curiosity: the methods of preparation described had purely academic value, and started with costly primary materials that (in those years, immediately after the war) it would be vain to hope to find on the market. The only reasonable preparation was the oldest; it didn’t seem so difficult to carry out, and consisted in breaking down uric acid by oxidation. Just that: uric acid, produced by the gouty, the incontinent, and kidney stones. It was a decidedly unusual primary material, but perhaps not so prohibitively expensive as the others.
In fact, further research on those very clean shelves, smelling of camphor, wax, and age-old chemical labors, taught me that uric acid, while it is very scarce in the excretions of man and other mammals, constitutes 50 percent of the excrement of birds and 90 percent of the excrement of reptiles. Very well. I telephoned the bully to say that the thing could be done, that he should just give me several days: within the month I would bring him my first sample of alloxan, and at the same time give him an idea of the price and of how much I could produce a month. That alloxan, intended to embellish ladies’ lips, should emerge from the excrement of hens or pythons was a thought that did not disturb me in the least. The occupation of chemist (reinforced, in my case, by the experience of Auschwitz) teaches us to overcome, indeed to ignore, certain kinds of disgust, which have nothing necessary or natural about them: matter is matter, neither noble nor vile, and infinitely transformable; its immediate origin is utterly unimportant. Nitrogen is nitrogen, it passes miraculously from the air to plants, from these to animals, and from animals to us; when its function in our body is exhausted, we eliminate it, but nitrogen it remains, aseptic, innocent. We, I mean to say we mammals, who in general do not have problems taking in water, have learned to embed nitrogen in the urea molecule, which is soluble in water, and we get rid of it as urea; other animals, for whom water is precious (or was for their distant ancestors), have come up with the ingenious invention of packaging their nitrogen in the form of uric acid, which is insoluble in water, and of eliminating it in its solid state, without needing to resort to water as a vehicle. In an analogous mode, people think today of eliminating urban garbage by making compressed blocks, which, at little expense, can be hauled to the dump or buried.
I will go further: far from outraging me, the idea of getting a cosmetic from an excrement, or, rather, aurum de stercore, gold from dung, amused me and warmed my heart, like a return to origins, when alchemists extracted phosphorus from urine. It was a novel, happy adventure, and noble, too, because it ennobled, restored, and renewed. Nature does likewise: it derives the grace of the fern from the rotting underbrush, and pasture from manure, letame, and doesn’t the Latin laetamen perhaps mean allietamento, gladness? So I was taught in school, so it was for Virgil, and so it became again for me. I returned home at night, explained to my very new wife the business of the alloxan and the uric acid, and told her that the next day I would be going on a business trip: that is, I would take the bicycle and go on a tour of the farms on the city’s outskirts (at that time they still existed) in search of chicken manure. She didn’t hesitate: she likes the country, and a wife should follow her husband; she would come, too. It was a kind of supplement to our honeymoon, which for reasons of economy had been humble and hurried. But she warned me not to delude myself: finding chicken dung in its pure state would not be so easy.
In fact it was difficult. In the first place, chicken manure (pollina, it’s called: we urbanites didn’t know it, nor did we know that, precisely because of the nitrogen, it’s extremely valuable as a fertilizer for vegetable gardens) is not given away; indeed, it’s sold at a high price. In the second place, the buyer has to collect it, crawling on all fours into the chicken coop and gleaning in barnyards. In the third place, what you are in effect collecting can be immediately used as a fertilizer but does not lend itself to further operations: it’s a mixture of manure, earth, stones, feed, feathers, and, in Piedmontese, përpôjín (these are chicken lice, which nest under the wings: I don’t know what they’re called in Italian). In any case, paying not a little, struggling and dirty, my fearless wife and I returned in the evening along Corso Francia, with a kilo of hard-earned chicken dung in the bicycle basket.
The next day I examined the material: much of it was gangue, yet something could perhaps be extracted from it. But at the same time I had an idea: an exhibit of snakes had just opened in the metro tunnel (which has existed in Turin for forty years, while the metro still doesn’t). Why not go and see? Snakes are a clean breed, they don’t have feathers or lice and don’t scratch in the dirt; then, too, a python is a lot bigger than a hen. Perhaps their excr
ement, at 90 percent uric acid, could be obtained in abundance, in pieces that were not too small, and in conditions of reasonable purity. This time I went alone: my wife is a daughter of Eve and she doesn’t like snakes.
The director of the exhibit and the attendants received me with astonishment and disdain. What were my credentials? Where did I come from? Who did I think I was, to show up like that, as if it were nothing, asking for python dung? But nothing to discuss, not even a gram; pythons are sober, they eat twice a month and vice versa: especially when they have little exercise. Their very scant dung is sold at the weight of gold: anyway, they, and all the exhibitors and owners of serpents, had permanent, exclusive contracts with the big pharmaceutical companies. I should clear off, and not waste any more of their time.
I devoted a day to roughly picking through the manure, and two more trying to oxidize the acid contained in it to alloxan. The virtue and patience of the old chemists must have been superhuman, or maybe it was only that my inexperience in organic preparations was immense. All I got was foul gasses, tedium, humiliation, and a cloudy black liquid that irremediably stopped up the filters and did not show any tendency to crystallize, as, according to the text, it should have. The dung remained dung, and the alloxan with its resounding name a resounding name. That was not the way out of the swamp: by what path would I then emerge, I the discouraged author of a book that to me seemed good but that no one read? Better to return to the colorless but secure schemes of inorganic chemistry.
Tin
“It’s a bad thing to be born poor,” I was reflecting, as I held an ingot of tin from the Straits over the flame of a Bunsen burner. Very slowly, the tin melted, and the drops fell hissing into a basin of water: on the bottom of the basin a fascinating metallic tangle was forming, with constantly changing shapes.
There are friendly metals and hostile metals. Tin was a friend: not only because, for some months, Emilio and I had been living on it, converting it into stannous chloride to sell to mirror makers, but for other, less overt reasons. Because it marries with iron, transforming it into gentle tinplate and depriving it of its bloodthirsty quality as nocens ferrum; because the Phoenicians traded it, and because it’s still extracted, refined, and loaded on ships in fabled distant countries (the Straits, indeed: as if someone should say the Sleeping Sunda, the Happy Isles, and the Archipelagos); because it is alloyed with copper to make bronze, an eminently respectable material, notoriously lasting and well established; because it melts at a low temperature, almost like an organic compound, that is, almost like us; and, finally, because it has two unique properties, with picturesque and barely credible names, properties never seen or heard (that I know of) by human eye or ear, yet faithfully handed down, from generation to generation, by all school texts, tin “pest” and tin “cry.”
The tin had to be granulated so that it would be easier to attack with hydrochloric acid. It serves you right. You were sheltered by the wings of that factory on the lakeshore—a bird of prey, but its wings were broad and strong. You wanted to leave its protection, fly with your own wings: serves you right. Now fly: you wanted to be free and you are free, you wanted to be a chemist and you are a chemist. Go on, grub among poisons, lipsticks, and chicken dung; granulate tin, pour hydrochloric acid, concentrate, decant, and crystallize, if you don’t want to suffer hunger, and you know about hunger. Buy tin and sell stannous chloride.
Emilio had set up the laboratory in his parents’ apartment; they were pious people, imprudent and patient, and, certainly, giving him the use of their bedroom they had not foreseen all the consequences. But you can’t go back: now the front hall was a warehouse of demijohns of concentrated hydrochloric acid, the kitchen stove (outside of mealtimes) was used to concentrate the stannous chloride in six-liter beakers and Erlenmeyer flasks, and the entire apartment was saturated with our fumes.
Emilio’s father was a majestic, benign old man, with a white mustache and a thundering voice. He had had many occupations in his life, all adventurous or at least strange, and at seventy he still had an alarming eagerness for experiment. At that time, he held a monopoly on the blood of all the cows killed at the old Municipal Slaughterhouse on Corso Inghilterra: he spent many hours of the day in a foul cave, its walls brown with coagulated blood, the floor soaked in putrefied sewage and frequented by rats as big as rabbits; even the invoices and the ledger book were bloody. From the blood he made buttons, glue, pancakes, blood sausage, murals, and polishing paste. He read exclusively Arabic magazines and newspapers, which he had sent from Cairo, where he had lived for many years, where his three children were born, where, with gunfire, he had defended the Italian consulate from an angry mob, and where his heart remained. Every day he went on his bicycle to Porta Palazzo to buy herbs, sorghum flour, peanut oil, and sweet potatoes: with these ingredients, and the blood from the slaughterhouse, he prepared different experimental dishes every day; he boasted of them and made us taste them. One day he brought home a rat, cut off the head and paws, told his wife it was a guinea pig, and roasted it. Since his bicycle didn’t have a chain guard, and his back was a little stiff, he put clips on the bottom of his pants in the morning and didn’t take them off all day. He and his wife, the sweet and imperturbable Signora Ester, born in Corfu of a Venetian family, had accepted our laboratory in their house as if keeping acids in the kitchen were the most natural thing in the world. We transported the demijohns of acid to the fourth floor in the elevator: Emilio’s father had such a respectable and authoritative look that no tenant had dared to object.
Our laboratory resembled a junk shop or the hold of a whaler. Apart from its offshoots, which invaded the kitchen, the hall, and even the bathroom, it consisted of a single room and the balcony. Scattered around the balcony were the parts of a DKW motorcycle that Emilio had acquired disassembled, and that, he said, he would some day or other put back together: the scarlet gas tank was astride the railing, and the motor, in a food safe, was rusting, corroded by our exhaust fumes. There were also some canisters of ammonia, relics of an epoch that preceded my arrival, when Emilio scraped along by releasing gaseous ammonia into demijohns of drinkable water, selling these, and polluting the neighborhood. Strewn everywhere, on the balcony and in the house, was an incredible quantity of junk so old and worn as to be nearly unrecognizable; only on careful examination could the professional components be distinguished from the domestic.
In the middle of the laboratory was a large wood-and-glass fume hood, our pride and our only defense against death by gas. Not that hydrochloric acid is really toxic: it’s one of those forthright enemies that come upon you shouting from afar, and so it’s easy to protect yourself. It has an odor so penetrating that anyone who can take cover doesn’t hesitate; and you can’t confuse it with anything else, because after breathing in a gulp you emit from your nose two quick plumes of white smoke, like a horse in an Eisenstein film, and you feel your teeth pucker in your mouth as if you’d eaten a lemon. In spite of our eager hood, the fumes from the acid invaded all the rooms: the wallpaper changed color, the handles and metal fixtures became dull and scaly, and every so often a sinister thud made us jump. A nail had become completely corroded, and a painting, in some corner of the apartment, had crashed to the floor. Emilio put in a new nail and hung the picture back in its place.
So we dissolved the tin in the hydrochloric acid: then we had to concentrate the solution to a fixed specific weight and let it crystallize by cooling. The stannous chloride separated out into small, graceful prisms, colorless and transparent. Since the crystallization was slow, we needed many receptacles, and since hydrochloric acid eats into metals, these receptacles had to be of glass or ceramic. In periods when we had a lot of orders, we had to mobilize reserve receptacles, which Emilio’s house had in abundance, anyway: a soup tureen, an enameled iron pot, a Novecento-style chandelier, and a chamber pot.
The next morning we collected the chloride and drained it: you have to be careful not to touch it with your hands, or a disgusting odor
clings to you. This salt is odorless in itself, but it reacts in some way with the skin, perhaps reducing the disulfide bridges of the keratin, and releases a persistent metallic stink that announces you as a chemist for several days. It’s aggressive, but also delicate, like certain unpleasant sporting opponents who cry when they lose: you can’t force it, you have to let it dry in the air at its convenience. If you try to dry it, even in the gentlest way, for example with a hair dryer or over a radiator, it loses its water of crystallization and becomes opaque, and your foolish clients don’t want it anymore. Foolish, because it would suit them: with less water there’s more tin and hence a better yield; but so it is—the client is always right, especially when he doesn’t know much chemistry, as is precisely the case with mirror makers.
Nothing of the generous good nature of tin, Jove’s metal, survives in its chloride (besides, chlorides in general are riffraff, mostly ignoble by-products, hygroscopic and not good for much of anything: with the sole exception of common salt, which is another subject entirely). This salt is an energetic reducing agent, that is to say, it’s eager to free itself from two of its electrons, and does so on the slightest pretext, sometimes with disastrous results. A single splash of the concentrated solution, which had dripped on my pants, was enough to cut them cleanly, like a scimitar’s swipe; it was the period after the war, so I didn’t have any others except my Sunday ones, and there wasn’t much money at home.
I would never have left the factory beside the lake, but would have remained forever correcting abnormalities in paints, if Emilio hadn’t insisted, boasting of the adventure and glory of working for oneself. I had quit with absurd audacity, distributing to colleagues and superiors a will in quatrains full of gay impertinences: I was well aware of the risk I ran, but I knew that the freedom to make a mistake grows restricted with the years, and if you want to take advantage you mustn’t wait too long. On the other hand, there’s no need to wait too long to realize that a mistake is a mistake: at the end of each month we did the accounts, and it became increasingly clear that man cannot live on stannous chloride alone, or at least I couldn’t, who was just married and had no authoritative patriarch behind me.