ABSTRACT
When Szent-Györgyi1 called water the “matrix of life,” he was echoing an old sentiment. Paracelsus, in the sixteenth century, said that “water was the matrix of the world and of all its creatures.”2 But Paracelsus’s notion of a “matrix”—an active substance imbued with fecund, life-giving propertieswas quite different from the picture that, until very recently, molecular biologists have tended to hold of water’s role in the chemistry of life. While acknowledging that liquid water has some unusual and important physical and chemical properties-its potency as a solvent, its ability to form hydrogen bonds, its amphoteric nature-biologists have regarded it essentially as the canvas on which life’s molecular components are arrayed. It used to be common practice, for example, to perform computer simulations of biomolecules in a vacuum. Partly this was because the computational intensity was challenging even without solvent molecules, but it also reected the prevailing notion that water does little more than temper or moderate the basic physicochemical interactions responsible for molecular biology.
