There are nearly one thousand species of larger moth in Britain, but more than three times as many small—and sometimes tiny—micro-moths. Far too many for them all to have names, so that when Clive had hold of that one, at the time I didn’t even know what it was. All I could think was, What an odd calculation to damage lots of beautiful large ones in order to catch such a dull, possibly nameless, tiny one. His strange behavior didn’t stop there. He pinched it neatly through the thorax with his thumb and index fingernails, which is a way of killing that usually you’d use only as a last resort—say, when you’re in the field and haven’t brought any killing fluid with you, or if you’re specifically trying to avoid the side effects of some of the poisons, such as the discoloring of ammonia or the stiffening of cyanide. Pinching is bound to mash the body a bit, and it’s certainly not the way I’d have chosen to kill a little moth like that. I’d have pricked it in the belly with a nitric acid needle.
“It’s Nomophila noctuella,” Clive announced finally, arranging it in a small pillbox.
I wasn’t to find out for two more years, on the day that Maud died, why he was so unusually interested in it.
Chapter 10
Bernard’s Challenge
A week after the convention, Clive received a simple telegram. It was from Bernard, who was, by that time, head of biological sciences at a northern university. It read simply:
YOU DO BRIMSTONE STOP
I’LL DO SWALLOW-TAILED STOP
IT’S A RACE STOP
BERNARD STOP
“Silly games,” Clive tutted, tossing the telegram dismissively into the wastepaper basket in the hall. “He’s supposed to be a professor now,” he added, walking through to the kitchen.
I had thought that would be the end of it so at first I didn’t take much notice. But—now here’s the funny thing—it turned out Bernard understood something about my father that I didn’t: that a challenge of this nature had an irresistible lure for him, that even against all rational judgment and time pressures on our mounting deadlines, he would never ignore it.
A moment after he’d dismissed it as frivolous, I saw Clive scribbling calculations on the notepad he carried with him in his jacket pocket for “observations,” but it was only after lunch, when he laid out his entire stratagem for assaying the Brimstone fluorescence, that I realized he was picking up the gauntlet. He still professed irritation at Bernard’s message, so I can’t think why he decided to waste valuable time and energy on it when we were already up to our necks in the grant-backed research.
To make all this perfectly clear, what Bernard was challenging us to was a race to assay the fluorescent compound in the two species of moth—him doing the Swallow-tailed and us the Brimstone. First we’d need to extract the compound, a fairly simple process of emulsifying the animal with a pestle and mortar and putting the resulting slurry through a series of alcoholic distillations. Assaying the compound would be easy too, if a little laborious: it’s a series of strategically devised chemical tests, the results of which would lead, by a process of elimination, like laboratory Cluedo, to the type of compound we were dealing with, if not to its specific empirical formula. There were lots of tests to do: the murexide test for uric acid; litmus test for pH; chromatography for solvency; hydrogenation, distillation, oxidization and acid/alkali reactions.
So what was the difficult bit of the enterprise? The challenge, as Clive put it, was not in the chemistry but in the cooking. It was a problem of quantities: to get enough of the fluorescing compound to do the assay, Clive had worked out that we were going to need to crush more than twenty-five thousand Brimstones.
So that was it. We went headlong into Bernard’s challenge.
You can’t just set up a light trap night after night and hope you’ll catch lots of Brimstones. By the time the hunting season is over you’d have only a few hundred. We needed thousands, and quickly, and for that some cunning was required. Clive devised an ambitious plan. First, we needed virgins.
Moths share our weakness for sweets and alcohol, and the Brimstone is no exception. If you take the time to make their favorite recipe, mix it in a little treacle and smear it on trees or fence posts, they will come from miles around to feast and, at the same time, get stuck to the treacle, ripe for collection. So Clive went into the pantry and, like a witch at a cauldron, set about mixing together a potion of exquisite attractiveness to Brimstones, whose particular tastes are for wine, fermented bananas and rum. In time he reappeared with a sticky, gloopy pot of sour-smelling treacle.
Clive knew when and where the Brimstones would be on the wing and want a little something sweet. Each morning and night, he consulted his barograph and plotted the hygrometer recordings, patiently awaiting the perfect conditions. Moths won’t come to sugar when the air current is northeast or easterly, or if the atmosphere is not to their liking. For the first three weeks the weather was lazy and calm, too clear, too hot or too dry, but in the middle of the fourth there was a sharp rise in the mercury. It was overcast at dusk, and the night became a little thick and heavy, tight and threatening, hot and thundery, not a breath of wind….
“Tonight,” said Clive, like a conjurer, “but the Brimstones won’t fly ’til ten.”
Just prior to the ten o’clock news on the wireless, we slopped the treacle in strips onto six of the lime trees down the drive, and just after the news we returned to collect fourteen fresh yellow Brimstone females, two pregnant and twelve virgins.
It was the virgins we particularly prized. Back inside, I squeezed their bottoms one by one, and out dripped the most powerful aphrodisiac known to nature. Males will seek it out from up to five miles away, even from within a closed smoke-filled room upwind. It was with this powerful potion that we were going to persuade all the male Brimstones in southwest Dorset to flock here to take part in our experiments.
As well as light traps, which we set along the hawthorn hedges, we hung the scent of virgins in lures all over the grounds and began to collect the Brimstone population of the surrounding countryside. They came each night in their hundreds and each day I had the laborious task of anesthetizing them in batches and sampling through them, gassing the males, saving the pregnant females, which we could breed from, and squeezing the virgins for more potion. It was like a military operation, the mass execution of the local Brimstone population, and I sat from dawn to dusk, for days and weeks, during that long deathly summer, separating those who were to be immediately gassed and those who were of more use to us alive.
That summer Clive and I were both so involved in our work that we’d break for a quick meal at seven, then work long into the night. The autumn that followed was particularly dreary, bringing days when the mist refused to lift, as if a daylong dusk had come forever to the Bulburrow valley. Looking back, I can see how I got caught up in Clive’s unhealthy obsession with his work but—you must believe me—I’m not about to make excuses for the problems that arose from it.