The Weed That Strings the Hangman's Bag

"London?" Aunt Felicity said. "London is always the same: all soot and pigeons and Clement Attlee. Just one damnable deprivation after another. They ought to have men with nets to capture those children one sees in Kensington and train them to run the power plants at Battersea and Bankside. With a better class of people at the switches, the current mightn't go off so frequently."

Daffy, who because of company was not allowed to read at supper, was sitting directly across the table from me, letting her eyeballs slowly and agonizingly drift towards one another, as if her brain had just died and the optic nerves and muscles were in their last throes. I would not allow her the satisfaction of a smile.

"I don't know what the world is coming to," Aunt Felicity went on. "I shudder to think of the people one meets nowadays — that man on the train, for instance. Did you see him on the platform, Flavia?"

I shook my head.

"Neither did I," she went on, "but I believe he kept back because he thought I'd whistle for the guard. Kept sticking his head into the compartment all the way down from London — asking if we were at Doddingsley yet. A rum-looking individual he was, too. Leather patches on his elbows and a bandanna round his neck like some brute of an apache dancer from Paris. It oughtn't to be allowed. I had, at last, to put him in his place.

"'When the train comes to a full stop and the signboard outside the window says "Doddingsley,"' I told him, 'we shall be at Doddingsley — and not a moment sooner.'"

Now it seemed that Daffy's brain had not only died, but that it had begun to curdle. Her right eye rolled off into one corner, while the other looked as if it were about to explode clean out of her head.

This was an effect she had been working on for years: the ability to bulge her eyes out in two different directions at the same time.

"A touch of the old exophthalmia," she had called it once, and I had begged her to teach me the trick. I had practiced in front of a looking glass until my head was splitting, but I could never manage more than a slight lateral googly.

"God moves in mysterious ways, His wonders to perform," she had said, when I reported my failure.

He did indeed. The very thought of Daffy's words had given me an idea.

"May I be excused?" I asked, already pushing back my chair. "I forgot to say my prayers this morning. I'd better see to them now."

Daffy's eyes uncrossed and her jaw dropped — I should like to think in admiration.

As I unlocked the door and walked into my laboratory, the Leitz microscope that had once belonged to Great-Uncle Tar shot me a welcoming gleam of brass. Here, close to the window, I would be able to adjust its reflecting mirror to focus a late beam of sunlight up through the specimen stage to the eyepiece.

I snipped a lozenge-shaped sample from one of the leaves I had brought from what I now thought of as the Secret Garden in Gibbet Wood, and placed it on a glass slide beneath the lens.

As I twiddled the focus, with the instrument set at one hundred times magnification, I found almost instantly what I was looking for: the barbed cystoliths that projected like thorns from the leaf's surface. I flipped the leaf over with a pair of tweezers I had pinched from Feely's mother-of-pearl vanity set. If I was correct, there would be an even greater number of these clawlike hairs on the underside — and there they were! — shifting in and out of focus beneath the snout of the lens. I sat for a few moments, staring at those stony hairs of calcium carbonate which, I remembered, had first been described by Hugh Algernon Weddell, the great botanist and globe-trotter.

More for my own amusement than anything, I placed the leaf in a test tube, into which I decanted a few ounces of dilute hydrochloric acid, then corked it and gave it a vigorous shaking. Holding it up to the light, I could see the tiny bubbles of carbon dioxide form and rise to the surface as the acid reacted with the calcium carbonate of the tiny spurs.

This test was not conclusive, though, since cystoliths were sometimes present in certain nettles, for instance. In order to confirm my findings, I would need to go a little further.

I was eternally grateful to Uncle Tar who, before his death in 1928, had bought a lifetime subscription to Chemical Abstracts & Transactions, which, perhaps because the editors had never been informed of his death, still arrived faithfully each month on the hall table at Buckshaw.

Piles of these enticing journals, each issue with a cover the exact blue of a mid-March sky, were now stacked in every corner of my laboratory, and it was among these — in one of the issues from 1941, in fact — that I had found a description of the then newly discovered Duquenois-Levine test. It was my own variation of this procedure that I was about to perform.