A is for Arsenic

A is for Arsenic: The Poisons of Agatha Christie
Kathryn Harkup

Kathryn Harkup is a chemist and science communicator, lecturing on “the quirky side of science”.
A is for Arsenic covers the poisons used by Agatha Christie in her detective novels. She gives you the science, and also real-life cases. It’s a gripping read, but the Christie fan will notice a few slips.

In Sparkling Cyanide, George Barton dies from drinking poisoned champagne. A folded paper, like the kind then used for headache powders, is found under the table. It tests positive for cyanide. Or could the poison have been transported in a Cachet Faivre? Harkup confuses paper and cachet – medicinal cachets were rice paper cases, like Flying Saucers (full of innocuous sherbet).

Harkup repeats the fanciful Victorian explanation that foxgloves (containing poisonous digitalis) were originally “folks’ gloves”, or fairy gloves. (Fairies were sometimes known as the “good folk”.)

In her discussion of The Pale Horse (spoiler alert), she wonders why the conspirators don’t even ask the test victim’s name – but they’ve been told she’s Mrs Easterbrook, and she’s taken a flat under that alias. The fake Mrs Easterbrook mysteriously falls ill, but how? Then narrator Mark Easterbrook “sees the vicar’s wife treating her dog for ringworm”. It’s his cousin, Rhoda Despard, who is doctoring her dogs.

Digitalis poisoning may make a person view everything with a yellow cast, and see haloes around lights. A portrait of Van Gogh's doctor shows him surrounded by foxgloves. A hint that he prescribed digitalis to his famous patient? Does this explain the famous sunflowers and Starry Night, Harkup asks? She concludes it may just be a coincidence.

Christie’s short story The World’s End takes place in Corsica. Elderly, snobbish Mr Satterthwaite has been hauled off to the island by an aristocratic friend. She’s a Duchess, how could he refuse? Glittering with antique diamonds, the titled lady insists on roughing it. In their rather shabby (cheap!) hotel they meet a young painter, Naomi Carlton-Smith. She’s from a “good” family, so the Duchess is keen to make friends. Naomi shows some of her work.

"Good gracious, child, there was never a sky that color — or a sea either." 
"That's the way I see 'em," said Naomi...
"I've no patience with that sort of thing. Give me — " 
"A nice picture of a dog and a horse, by Edward Landseer." 
"And why not?" demanded the Duchess. "What's wrong with Landseer?" 
"Nothing," said Naomi. "He's all right. And you're all right." (The Mysterious Mr Quin)

Beware trying to explain away modern art as mere anomalies of vision. Dr Patrick Trevor-Roper did it better in The World through Blunted Sight.

More on Christie here.