Through years of research into water dilutions, Professor Luc Montagnier has developed a profound scientific understanding of the biological effect of the potentized remedies employed in Homœopathic Medicine. In this context, the role of high-water dilutions will be explained through an examination of the structure of water and its ability to imprint information. A  review of recent models of structured water will be presented, including the role of the solid phase of water. Professor Luc Montagnier won the Nobel Prize in 2008 for discovering the Human Immunodeficiency Virus.