1Boltzmann was dead, and his equation was on the stone. He had counted the ways of the smallest things, and he had gone through the Last Door believing that few would ever grant him that the smallest things were there at all.
2But the ember does not wait for a funeral. Go back a few years, to the last winters of the old century, and to a shed in the city of Paris. For while the old man was still fighting for his atoms, a woman was already taking one apart.
3Her name was Maria, and she came from Warsaw, in Poland, which in those days was on no map. Three crowns had cut her country into three pieces and forbidden its tongue in its own schools. As a girl she had learned her people's history in secret, with a lookout on the stairs.
4In her country a woman could not enter the house of learning. So she worked six years as a servant-teacher in other people's houses, and sent her wages to her sister, and when her turn came she rode to Paris in the cheapest wagon of the train, sitting on a folding stool she had brought herself.
5She lived under a roof where the water froze in the basin. She put her coat and her one chair on top of the blanket to press some warmth down upon her. Once she fainted from hunger over her books. She was happier than she had ever been.
6In Paris they called her Marie. There she met a quiet man named Pierre Curie, who studied crystals and magnets and did not care for honours. He had said that a woman of real mind was a rare thing and he did not expect to find one. Then he found one. They were married in plain clothes, and for their wedding journey they bought two bicycles.
7Now hear what the work was.
8A man of that city, Becquerel, had left a lump of the metal uranium in a dark drawer on top of a wrapped plate, the kind that takes pictures by light. When he opened the wrapping, the plate was fogged, as if light had struck it. But there had been no light. The stone itself was giving off something, day and night, with nothing feeding it.
9Few thought much about it. Marie thought about nothing else. She took it for her study, and she went through every stone and salt she could beg, measuring which ones gave the unseen rays and how strongly.
10And she found a thing that did not fit. There was a black ore from the mines of Bohemia, called pitchblende, from which uranium was taken. The ore gave rays four times stronger than all the uranium in it could explain.
11She measured again. She measured twenty times. The number stood.
12"Then there is something else in the ore," she said to Pierre. "Something no one has named. There is very little of it, and it is very strong."
13Pierre put down his crystals and came to work beside her, and he did not take them up again.
14Within the year they had found the tracks of two new things. The first she named polonium, so that the name of her erased country would be written into the list of the elements, where no crown could reach it. The second they named radium, the thing that rays.
15But a track is not the animal. The learned men of chemistry said, fairly: "You have shown us a glow on a plate. Show us the stuff. Put it in a bottle. Tell us its weight."
16To do that, they would have to get it out of the ore. And there was so little of it in the ore that they would need not a handful of pitchblende but tons.
17They had no money for tons. So Marie reasoned thus: the mine-owners take out the uranium to sell to the glass-makers, and throw the rest in a heap in the pine woods. What I want is still in the heap. And she wrote to Vienna, and the heap was given to her for the cost of carting it.
18It came in sacks, on a coal wagon. She cut the first sack open in the street, and plunged both hands into the brown dust. It was mixed with pine needles from the forest of Bohemia.
19They had no proper room to work in. The school where Pierre taught lent them a shed across the yard. It had been a place where students of medicine cut up the dead, and it had been given up as unfit even for that. It had a floor of tar, a roof of cracked glass that let in the rain, and one iron stove that warmed nothing more than an arm's length away.
20For four years that shed was her whole world. She took the ore twenty kilograms at a time. She ground it, and boiled it in iron pots, and stirred the boiling mass for hours with an iron rod as tall as herself. She poured and strained and boiled again. The smoke of it burned her eyes and throat, so she worked in the yard when the weather let her, and when the rain came she dragged the pots back inside and opened the windows.
21Each boiling left a little less, and what was left was a little stronger. A cauldron became a pot. A pot became a bowl. A bowl became a dish.
22At evening she could not lift her arms. Pierre said to her once, in the third year, "It is too hard. We could stop here. The rays are proven. Let others get the stuff out, with money and a real room."
23"It is in there," said Marie. "I have carried it this far."
24They had a small daughter by then, Irène, whom Pierre's old father minded. Marie would walk home to bathe the child and put her to bed, and sit by her until she slept. Then she would say to Pierre, "Shall we go back for a moment?"
25And they would walk through the dark streets to the shed, and open the door, and not light the lamp.
26Listen to what they saw.
27On the rough shelves and tables stood the dishes and bottles of four years' labour. And every one of them was shining. A soft blue-green light hung in each, with no flame in it and no heat to be seen. It did not flicker. It lit the edges of the glass and nothing else. Long after, she wrote of those nights: "The glowing tubes looked like faint, fairy lights."
28They stood in the dark, the two of them, not speaking. No one on the earth had seen that light before. It had been burning inside the stone since before there were eyes.
29In the fourth year she had it. One tenth of a gram of pure radium salt lay in a dish: as much as would cover a fingernail, from a hill of ore. She weighed its atom, and wrote the number down, and the chemists had no more to say.
30Now mark what the radium did, for it broke the peace of the old century.
31It was warm. It was always a little warmer than the room it sat in. It could melt its own weight of ice in an hour, and the next hour do it again, and the next, and it did not cool and it did not grow less that any scale could show.
32The masters of heat had taught that no fire burns without paying. Carnot had said it, and Clausius had made it law. Here was a stone that seemed to pay nothing. Wise men were troubled. Some said the great law was broken.
33It was not broken. The stone was paying; it was paying out of a purse so deep that no one had known it was there. For it came to be understood, by Marie and by others after her, that the rays did not come from atoms joining or parting, as in a common fire. They came from inside the atom itself. The atom was coming apart.
34Think what that meant. For two thousand years atom had meant the thing that cannot be cut: the last small stone, hard and blind, with no inside. Now it had an inside. It was a house with rooms, and in the rooms a fire was banked that made a coal fire look like a spark.
35There was a second thing the radium did, and they were slow to read it. Marie's fingertips grew hard and cracked, and pained her. Pierre tied a little of the salt against his arm for some hours, to see what would come; a burn came, red and deep, and took two months to close. Becquerel carried a tube of it in his pocket and was burned through his clothes.
36Pierre was glad of his burn. "If it can kill flesh," he said, "it can kill sick flesh." And so it proved. The doctors tried the rays on the growths that eat a body from within, and some of the growths withered. People who had been sent home to die began to come to Paris.
37But the same rays were working in the two of them, quietly. Pierre's legs ached at night. His hands shook so that some mornings he could not button his coat. Marie was tired in a way that sleep did not mend. They called it overwork. They did not know that the pretty light at their bedside was a door that opened both ways.
38Then, one Sunday morning, a letter came from across the sea. Some engineers of America wished to make radium, and asked how it was done.
39Pierre laid the letter on the table. "There are two roads," he said. "We may tell them freely, and tell everyone, all that we know. Or we may say that the method is ours, and seal it with a patent, and be paid by every maker in the world."
40They were poor. He taught long hours for small pay; she taught girls at a school two hours away. They still had no proper room. A patent would have bought them the finest house of learning in France, and ease for their daughters after them.
41Marie thought for a little while. Then she said, "No. It is not ours in that way. And it is going to be used for the sick. I will not stand at the door of that and take a coin from each one who passes."
42"No," said Pierre. "It would not be right." And that evening he wrote to the engineers, and gave them everything.
43So the way of making radium went out to the world as a fire goes from horn to horn, and was not smaller for it. Within a few years a gram of it cost more than a great house, and the Curies owned no part of that. She never said that she was sorry.
44Then came a Thursday in April, with rain.
45Pierre had been to a meeting of his fellows. He walked home under his umbrella, thinking, as he always walked. At a narrow crossing near the river, he stepped out from behind a cab into the road. A heavy wagon with two horses was coming down, loaded with soldiers' cloth, six tons of it. He slipped on the wet stones. The driver hauled on the reins with all his strength. The front wheels missed him. The back wheel did not.
46It was over at once. He was forty-six.
47They told Marie in the evening. She stood very still. She asked them to say it again, as if the word dead might have some smaller meaning that she had not been told. Then for many days she said almost nothing at all.
48She kept a grey notebook in those weeks and wrote in it to him, as if he were in the next room. She told him that she had put a picture of the two of them in the coffin. She told him that the buds had opened on the trees, and that she could not bear the sun.
49The state offered her a widow's pension. She refused it. She was young enough, she told them, to earn bread for herself and her children.
50Then the university did what it had never done in all its six hundred years. It gave a master's chair to a woman: his chair, to her.
51On a day in November she walked into the hall where he had taught. Every bench was full, and people stood along the walls and out through the doors into the square: students, and great ladies, and men from the newspapers, and Poles of the city who had come to see their countrywoman. They waited for her to speak of her husband. They waited for tears, or thanks.
52She came in by the small door at the back, a thin woman in black, and laid her notes on the long table, and gripped its edge until the clapping stopped.
53Then she began to speak about the workings of the atom. She began at the very sentence where Pierre had stopped, in his last lesson, in that room, in the spring.
54She did not say his name. She did not need to. A man goes through the Last Door, and the lesson he was giving is found open on the table, and someone picks it up in the middle of the line.
55People wept in the benches who had not come to weep. She went on to the end of the hour, in a low even voice, and gathered her notes, and went out by the small door.
56It is easy to believe that she went that night to the place where the radium was kept, and did not light the lamp.
57Her notebooks from the shed are still kept in that city. They lie in boxes of lead, and those who wish to read them must sign a paper first, for the pages give off the unseen rays to this day and will go on doing so for many lifetimes.
58She had found a new kind of ember, one that needed no moss and no breath, that burned inside the smallest thing there is. She held it up in her cracked fingers for everyone to see. And she, who had taken nothing for it, could not yet know what others would one day build of it.