50 and 100 Years Ago in The Journal of Physical Chemistry – 2025 Edition

50 and 100 years ago.In 1925, The Journal of Physical Chemistry published 153 articles, a 40% increase from the previous year and continuing the trend of journal growth in the 1920s.A large number of the papers dealt with the properties of colloids and emulsions, which was an important topic at the time and a major focus of the Journal's editor-in-chief.The most prolific authors were N. R. Dhar from the University of Allahabad, India, and W. A. Patrick from Johns Hopkins University with eight papers each.Patrick pioneered a method to quickly and cheaply produce silica gel, which has a variety of uses, an important example being as the active agent in gas masks in World War I. His papers and correspondence have been archived by Johns Hopkins University.All of Patrick's papers published The Journal of Physical Chemistry in 1925 were studies of absorption of different species onto silica gel, except for a study of boiling points and conductivity of soap in alcohol solutions.1 The soap study showed, not too surprisingly, that sodium oleate is dissociated in alcohol solutions at the boiling point.Dhar published on a wide range of topics including the viscosity of colloid solutions, 2 studies of corrosion of metals by nitric acid, 3 how the color of colloidal solutions changes with ion adsorption, 4 and photosynthesis in tropical light compared to artificial UV light.5 Dhar was an extremely prolific scientist, and was an early leader of physical chemistry in India.