Winner of the NSW Premier's Literary Award When Dr William Macbeth poisoned two of his sons in 1927, his wife and sister hid the murders in the intensely private realm of family secrets. Macbeth behaved as if he were immune to consequences and avoided detection and punishment. Or did he? Secrets can be as corrosive as poison, and as time passed, the story haunted and divided his descendants. His granddaughter, Gail Bell, spent ten years reading the literature of poisoning in order to understand Macbeth's life. Herself a chemist, she listened for echoes in the great cases of the nineteenth century, in myths, fiction, and poison lore. Intricate, elegant, and beautifully realised, The Poison Principle is a masterful book about family secrets and literary poisonings. Praise for The Poison Principle by Gail Bell 'Miraculously well written, compellingly readable ... a book of rare distinction.' The Times '[Bell's] solution to the mystery was - and is - a triumph of perseverance ... enthralling.' The Guardian '[The Poison Principle] … measures out, in small loving spoonfuls, grains of information about [a] family story … Between the quiet drip feed of her personal memoir, Bell mixes in stronger flavors: ingredients from criminology and psychology, botany and chemistry.' The New York Times 'A gift of a story and Bell tells it to near perfection.' The Age 'An elegantly written memoir about her search for the truth behind her family's darkest secret … a fine thriller, a richly detailed pharmacopoeia and a splendid dissertation on references to poison in literature.' The Sydney Morning Herald