Progress in Biophysics and Biophysical Chemistry, Volume 9 reviews developments in biophysics and biophysical chemistry and covers topics such as the kinetics of reactions between hemoglobin and gases; the hydrodynamics of the arterial circulation; visual pigments in humans and animals and their relation to seeing; and gradient centrifugation of cell particles. The conversion of mechanical energy into electrical energy in certain mechanoreceptors is also discussed. This book is comprised of seven chapters and begins with an overview of the general properties of hemoglobin and its reactions with gases, and how such reactions are affected by temperature. The intermediate compound theory and the combination of sheep hemoglobin with carbon monoxide are also considered. The following chapters explore the diffusion and simultaneous chemical reaction velocity in hemoglobin solutions and red cell suspensions; the hydrodynamic aspects of the arterial circulation; determination of molecular dimensions from light scattering data; and the relation of receptor potentials to the activity of complex mechanoreceptor organs containing hair cells. The final chapter is devoted to the theory and applications of the gradient centrifugation of cell particles. This volume will be of interest to both biophysicists and biochemists.