Eric Flint: Grantville Gazette.Volume 22

"More likely asked for a cut in return for his silence, and got too greedy," said Cosimo.

"But were those rivals at the dinner?" asked Marina.

"Even if they weren't there, they could have suborned a servant," said Cosimo. "But actually, I think it's the wife. Wives have poisoned inconvenient husbands since time immemorial. A half-century ago, Bianca Cappello, the most beautiful woman in Tuscany, poisoned Pietro Bonaventuri, so she could marry her lover, Francesco de Medici."

"Yep, Silvia's a suspect, all right. Silvia would have much more financial independence as a widow, and she's still good looking. For that matter, perhaps there's some young fellow she already has her eyes on."

"We'll look into it," said Cosimo.

"Then there are the heirs," Lewis continued. " Domenico and Olimpia. You do know what they call arsenic in this day and age? 'Inheritance powder.' It can be added to food or drink without imparting a suspicious color or taste, and seventeenth century alchemy is quite incapable of identifying it. That made it the ideal poison until chemistry caught up with the poisoners in the nineteenth century."

"Rocco got chummy with Taddeo, found out that Pietro's got a mistress. Had a mistress, I should say. Her name's Stella. Lives at a nice address, dresses well. Sin pays."

"Ah," said Lewis, "the plot thickens. Or, more precisely, the list of suspects increases."

Marina looked unconvinced. "Why would she kill the goose that lays the golden eggs? Surely she would be left with nothing if he died."

"Right," said Cosimo. "Usually the mistress gets rid of the wife, and marries the husband. Bianca Capello did that, too. Remember her? She poisoned Giovanna, the Austrian princess, and married Francesco de Medici."

Lewis shrugged. "A mistress might murder a patron. Perhaps she found a fatter 'goose,' and Pietro wouldn't let her move on. Or perhaps he beats her, and she wanted revenge. Or he refused to divorce his wife, and she decided to poison Pietro and hope that the death would be blamed on Silvia."

Marina had a different idea. "Or perhaps some young fellow is madly in love with Stella and killed Pietro out of jealousy."

"You're quite a romantic," said Lewis.

"No, no, your sister's right," said Cosimo. "That sort of thing happens. I'll ask around."

"Perhaps I should interview this Stella myself."

"How very conscientious of you, dear brother."

Cosimo found Stella's boy toy. "His name's Fabio," Cosimo reported.

"Occupation?"

"Artist."

"Great, all I need," said Lewis.

"What's wrong with artists? Even artists named 'Fabio'?" asked Marina.

"The pigments they use. Which include realgar red and orpiment yellow. Realgar is arsenic (II) sulfide, and orpiment is arsenic (III) sulfide."

"While those are poisonous, you can't put them in food without anyone noticing," said Cosimo.

"But you can react them with natron, sodium carbonate, to get arsenic trioxide. And heat that in vegetable oil if you want pure arsenic. As I said, all I need."

Lewis started pacing, then stopped abruptly. "Although while this Fabio may have had the means, and the motive, I am not so sure he'd have the opportunity. When would he come into contact with Pietro?"

"Perhaps he gave the stuff to Stella to administer to Pietro. He might not even have told her it was poison. Perhaps that it was an aphrodisiac."

Lewis snorted. "We're making quite a mountain of accusations out of a molehill of evidence."

Lewis knew that Pietro's body contained a large dose of arsenic, the Marsh test on his stomach contents was ample proof of that. If the arsenic had been administered on the day of the infamous dinner, then the list of suspects could be trimmed down, to just the family, the guests and the servants present that day. Still a long list, of course.

But Pietro and Silvia thought that there had been a series of attempts on his life. And if that were the case, and they were all by the same party, then knowing when the attempts were made could help narrow down the list of suspects.

Unfortunately, the Marsh test didn't provide a timeline. The statements collected by the investigators, and even the household account book, hadn't been of much help, either. There were payments for medicines, but the responsible doctors and apothecaries swore that these didn't contain significant amounts of arsenic, and Lewis' testing of the remaining vials, ointments and whatnot confirmed that. In fact, it seemed that Pietro had the least chronic exposure to arsenic of anyone in the household.

Lewis had one last resort. Back in 1997, the high school had been the recipient of an extraordinary gift, a $300,000 atomic absorption spectrophotometer. The gift had come about because one of the high school teachers had led a statewide high school science club trip to Carnegie Science Center in Pittsburgh, and had run into some LaFarge executives there.

As the name suggested, the AAS atomized a sample and then analyzed its ability to absorb light of different wavelengths. It should be able to detect arsenic at a level of just one part per million. Perhaps less.

"It's been a month since Pietro died, Dottore," Ferdinand said. He and Lewis were sitting in Ferdinand's laboratory, a corner of which had been appropriated by Lewis. "Can this wondrous AAS of yours still find the poison?"

"That's the good thing about an elemental poison, like arsenic, or thallium, your Grace. The body can kick it out, but it can't decompose as it can, oh, snake venom. Within an hour or two of ingestion, the arsenic is distributed all over the body, even in the hair roots. Within a few days, it can be detected in the hair above the skin. And if the victim died with arsenic there, it will be still be there a month, a year, a decade, even a century later. The arsenic atoms stick very well to the sulfur atoms in the hair."

"A century, are you sure?".

"That's right. In the nineteenth century of the old time line, there was an emperor of France named Napoleon. He got defeated by the Brits and sent into exile on an island. He died there, and some people thought he had been poisoned. Over a century after his death, someone took a lock of hair that Napoleon had given to one of his aides, and had it tested with modern equipment for arsenic.

"Sure enough, he had way more than normal levels of arsenic."

"Wow!" said Marina, who had been invited to look at Ferdinand's chamber of curiosities. "Napoleon was poisoned!"

"Well, not necessarily deliberately," Lewis admitted. "There was a green wallpaper used at that time, which contained an arsenical dye. They didn't know that it could be decomposed by bacteria to release arsine gas, which is really nasty stuff."

"A hundred years…" muttered Ferdinand.

"I beg your pardon, Your Grace. What did you say?"

"Never mind that for now. You already know that he was poisoned, from the contents of his stomach, so why look at his hair?"

"Because the hair would chronicle his arsenic exposure. Hair grows from the root outward, at a rate of a centimeter a month. So if his hair were twelve centimeters long, we could cut into sections and know when he ingested arsenic over the past year or so."

"Marvelous. And so you could eliminate any suspects who were absent when he had an arsenic peak," said Ferdinand.

"Exactly."

"Would you know the very days of each poisoning attempt?"

"I wish. To narrow down the time, you need to test shorter segments of hair, and there is more of a chance of contamination of the segment with arsenic from other sources. And that one centimeter a month is an average, it varies from person to person, and even from one part of the head to another. But we should be able to pin it down to a particular month, maybe even a particular fortnight.