This book is unique and very worthwhile to read! I would count it as a 'living book' about chemistry. Living because while it explains the chemistry behind many elements known now to be poisonous, it is told not from a dry technical perspective but within the context of people that were affected by living with medical treatments that were actually poisonous dosing and other situations where they came in contact with these various elements. Each element is explained from a chemical structure perspective, how it reacts chemically and why, how it was discovered and what it does to the human body. It is a book with real history in it, because as the author explains the chemical properties this is done in conjunction with many different "sudden deaths" in the past that can now probably be diagnosed as due to poison.For those who are interested in murder mysteries, some of the stories read indeed like Agatha Christie. Some of the people discussed include Napoleon (death by arsenic, but probably because there was arsenic in the paint in the wallpaper where he was staying?), the madness of King George III (lead poisoning combined with a genetic illness?), and many others. Elements examined include mercury (implicated in the death of Charles II who had his own basement laboratory with little to no ventilation), arsenic, antimony, lead, thallium, and another chapter of miscellaneous elements.VERY interesting! It makes you REALLY appreciate living in the current day and age...instead of in the past when food was stored in containers that had lead glaze on them, or drinking from bottles sealed with lead solder, or eating from canned food that had been tainted with lead solder when sealed, or were given medical treatments that included arsenic or mercury.... YIKES!