Physical and Electrochemistry

1799 

• Alessandro Volta develops his electric "pile"      

150 years ago
1849 

• Gustav Wiedemann  demonstrates relations between the electrical conductivity and the structure of crystals
• Herman Kolbe electrolyses salts of fatty acids which develop radicals      

100 years ago
1899 

• Arthur Hantzsch develops the concepts of ionisation isomerism, pseudo-acids and pseudo-bases and further the determination of the constitution of tautomer tic compounds
• Harold A Wilson determines the velocity of ions in flames containing salt vapour
• Philipp Lenard  observes that oxygen is ozonised by ultraviolet rays
• Gustav Tainmann  conducts accurate measurements concerning the influence of very high pressures on the change of the melting heats on about 30 compounds
• Mahler improves the caloric bomb of Berthelot (1879) by using an enamelled steel cylinder instead of a platinum one
• Manlay invents the ozotypy (ozobromine pressure), the photographic method using papers coated with a mixture of potassium bichromate and gelatine      

50 years ago
1949 

• Ronald George Wreyford Norrish and George Porter  develope the flash photolysis
• William Giaugue  receives the Nobel Prize for Chemistry for studying thermodynamics at very low temperatures