The two oldest spring holidays in this town arrive by the moon, not the calendar, which is why nobody can ever remember from one year to the next when they fall. Passover begins at the full moon of the first month of spring. Easter, in the western churches, comes on the Sunday after a full moon of its own, reckoned by an old church table rather than by the sky, and most years the two land within a week of each other; now and then they fall a month apart. So there is a stretch nearly every spring when one set of families in Baytown is clearing the bread out of the house and another is buying lilies and a ham, and somewhere in a grocery on Garth Road there is a box of matzah on an endcap next to the plastic eggs, or ought to be, and the bay is the same for all of them: warm in the afternoon, cool at night, the mullet jumping.
I am not going to explain either holiday to the people who keep it. They know it better than I do. I'll say only what is plain from the outside. One is about a people who walked out of a country where they were owned, and who eat once a year the flat bread of a departure so sudden there was no time to let the dough rise. The other is about a man who was killed and buried and whose friends found the tomb empty. Both are told to children at a table. Both are about something that was supposed to be over and wasn't. That is as far as I'll go, and if you keep either holiday you can take the rest of this essay as one neighbor's way of thinking near it, not about it.
Because there is a spring story this town tells that is neither of those and belongs to everyone, and it starts with a Frenchman and a sealed glass jar.
His name was Lavoisier, and near the end of the eighteenth century he did something that sounds too simple to matter. He weighed things before and after he burned them. Not roughly: precisely, on the best balances that could be made, with the whole apparatus sealed so that nothing could escape or enter. He heated tin in a closed vessel, and the tin gained weight, and the air in the vessel lost exactly that much, and the sealed vessel as a whole weighed what it had weighed before. He heated mercury in air for days until a red crust formed on it, and the crust weighed more than the mercury had. Then he heated the crust until it gave back a gas and turned to bright metal again, and the gas weighed what the crust had gained. He did this over and over, with different substances, and the answer was always the same. Whatever happened inside the jar, however violent, the total weight at the end was the total weight at the start.
That's it. That is conservation of mass. In a chemical change, nothing is created and nothing is destroyed. The atoms are rearranged. They trade partners. They leave one arrangement and enter another. But the count is exact. If you burn a log in a fireplace and could somehow catch every bit of smoke and ash and water vapor and gas that leaves it, and weigh them, and weigh the oxygen the fire pulled from the room, the numbers would balance to the last fraction of a gram. The log is still in the room, in the chimney, in the sky over the house, in a different shape. Strictly, a little of the mass does leave as the heat of the fire; Einstein worked that out; but the amount is so small that no balance ever built could see it, and for anything that burns in a fireplace or a furnace, Lavoisier's answer stands.
Every schoolchild in Goose Creek CISD meets this rule by the time they leave middle school; it's in the state's list of what an eighth grader has to know. Most of them forget it, which is fine. But there is a building on the ship channel that is, in a sense, a monument to it, and a good part of the town works there or knows someone who does.
An olefins plant, a cracker, is a machine for taking a molecule apart. The feed is a hydrocarbon, often ethane, a simple thing: two carbons holding hands, each one wearing three hydrogens. The plant mixes it with steam and drives it through a furnace tube where the temperature is somewhere between eight and nine hundred degrees Celsius, hot enough that the molecule cannot hold itself together. It shakes apart. Two hydrogens fall off. What is left is ethylene: still two carbons, now holding on to each other with a double bond, wearing only two hydrogens apiece. The hydrogen that fell off doesn't vanish. It comes out the other end of the plant as hydrogen gas and is caught and burned in the furnaces or sold. The steam comes out as water. Some of the ethane breaks the other way and comes out as methane, and some of the carbon sticks to the inside of the furnace tubes as coke, black and hard, until the furnace is taken off line and the coke is burned out with steam and air and goes up the stack as carbon dioxide. The plant has a name for all of this, the material balance: every pound in, accounted for as a pound out, in one stream or another. The plant is not making matter. It is sorting it.
And ethylene, the sorted thing, is the most-produced organic chemical on earth. It goes down a pipe to the next unit and is stitched into chains, thousands of ethylene units long, and the chains are polyethylene, and polyethylene is the milk jug and the grocery bag and the pipe under your street and the film over the pallet of bottled water at the shelter after a storm. The carbons in the jug in your refrigerator were once two carbons in a molecule of ethane that was once part of a plankton that was once alive in a warm sea before there were flowers. They have been rearranged, a great many times. They have not been destroyed.
Ethylene is also a hormone, and I have never quite got over that. Plants make it themselves, in tiny amounts, and it is the signal that tells a fruit to ripen and a flower to open and a leaf to let go in the fall. The tomato on the windowsill is making ethylene right now, a few parts per million, and that is enough. The same molecule, the same two carbons and four hydrogens, whether it comes out of a furnace on the channel or out of a pear. Chemistry does not know the difference and there is no difference to know. A molecule is what it is made of and how it is arranged. It has no memory of where it was made.
I'll take the next step slowly, because it's the kind of thing that can sound like a sermon if you rush it, and it isn't one.
Spring, everywhere people have lived, is the season of things coming back. The wheat comes up. The trees on Texas Avenue that looked dead in February put out leaves. The birds that left in October land in the Nature Center on their way north, thin from crossing the Gulf. The two holidays sit in this season for a reason, and it isn't an accident that they are both, at bottom, stories about something that ended and then didn't.
Chemistry has its own version of that, and it is smaller and stranger and, I think, worth holding next to the others without confusing it with them. Chemistry says: you cannot lose anything. You can only lose track of it. The log in the fireplace is not gone; it is dispersed. The water you drank this morning has been in the sea, in a cloud, in a Roman soldier, in a dinosaur, in the bay, and in you, and every single molecule of it is still somewhere, doing something. The carbon in your body was in the air last year and in a plant before that and in the air again before that, back and back, and some of it, for all anyone can say, was in the ground under Goose Creek before the first derrick, and came up, and was burned, and went into the sky, and was taken in by a leaf, and was eaten, and is now you. The atoms in your hand have been a lot of other things and will be a lot of other things again. The count is exact. Nobody has ever caught the universe losing one.
I don't think this replaces what the holidays are about. A person is not a pile of atoms in the way that a log is a pile of atoms; if she were, we wouldn't grieve. What I think is that a town that makes its living by taking molecules apart at nine hundred degrees and putting them back together as something useful has a right to notice that its daily work is a demonstration, run around the clock, of the one thing in nature that comes closest to the promise the holidays make. Nothing is destroyed. Everything is rearranged. The furnace and the tomato are doing the same thing with the same molecule, one of them at nine hundred degrees and one of them on a windowsill.
There's a picture in the operator training rooms, or there was in one I saw years ago, of the material balance on a unit: what comes in on the left, what goes out on the right, and the two columns adding up to the same number. Somebody had written under it, in pen, the balance always closes. It was meant as a joke, the way an operator's jokes are, since a balance that doesn't close means something is leaking, and finding the missing pound is a real job. But it's true in the larger sense too. The balance always closes. It has closed every second since the world began, without anyone watching, and it will close tonight on every unit on the channel, and it closed in that glass jar in Paris while a man with good scales wrote down the number.
Lavoisier, by the way, was killed in the revolution a few years after he did that work. He was a tax collector for the old regime as well as a chemist, and the new regime did not care about the scales. There is a line about it that has been attributed to a mathematician who knew him, that it took an instant to cut off his head and a hundred years might not produce another like it. I don't know if the line is genuine. I know the work was, and I know that the man is gone and the balance he found is not, and I know the atoms of him are somewhere in France, or in the sea, or here.
So it's spring on the bay. One family will clear the flour out of the pantry and one will hide eggs in the grass at Roseland Park and a good many will do neither and go fishing, and above all of them, on the channel, a furnace will be running at nine hundred degrees, taking a molecule from a sea that dried up before there were flowers and turning it into a thing that will hold milk. The mullet are jumping. The count is exact. In the yard, on a windowsill, a tomato that was green on Friday has started, on its own and by the same molecule, to turn.
