Preface

I hope to entice the scientist and other readers of this book in equal measure. Poisons have two stories to tell. The science of poisons deals with the chemistry of toxic agents and the way they work at the cellular and molecular level. The art of poisons encompasses everything else about these agents that congers up the image of the skull and crossbones.

The science of poisons takes us on a voyage into the sub-microscopic world of atoms, molecules, and cells. Only there can we see the true miracles and mysteries of life and death. The mere existence of poisonous substances and especially the uses made of them by plants and animals are wondrous. Poisons are also used to explore the biological mechanisms of the body, to lower cholesterol by blocking its synthesis, to kill cancer cells, to destroy pests of all kinds, and as weapons of war. Science is neither moral nor amoral, only its uses can be so characterized.

The art of poisons encompasses everything else about poisons. It is the legends and stories of intrigue and murder and other deeply deplorable uses of toxic agents often with a surreptitious and evil intent. Let us hope that the future extends the beneficial applications of poisons and quells their evil uses.

A traditional, central concept in toxicology can be stated simply: the lethal dose of a substance is the amount required to kill the average person (the LD50). Today for most poisons, the mechanism of how they kill is known at the molecular level. Therefore, I propose that a new measure of toxicity based on the number of molecules required to kill (the LD₅₀*) is appropriate.

The simplest summary idea about poisons is one of the oldest ̶ the dose makes the poisons (paraphrased from Paracelcus). I believe the most extreme example is the toxicity of oxygen. Oxygen is essential; we cannot live more than a few minutes without oxygen; however, it is detectably toxic at approximately two times the concentration found in air, and at hyperbaric pressures it is lethal.