The renowned English chemist and meteorologist John Dalton (1766–1844) published A New System of Chemical Philosophy in two volumes, between 1808 and 1827. Dalton's discovery of the importance of the relative weight and structure of particles of a compound for explaining chemical reactions transformed atomic theory and laid the basis for much of what is modern chemistry. Volume 2 was published in 1827. It contains sections examining the weights and structures of two-element compounds in five different groups: metallic oxides; earthly, alkaline and metallic sulphurets; earthly, alkaline and metallic phosphurets; carburet; and metallic alloys. An appendix contains a selection of brief notes and tables, including a new table of the relative weights of atoms. A planned second part was never published. Dalton's work is a monument of nineteenth-century chemistry. It will continue to be read and enjoyed by anybody interested in the history and development of science.