FRANKLAND, SIR EDWARD (1825-1899), English chemist, was born at Churchtown, near Lancaster, on the 18th of January 1825. After attending the grammar school at Lancaster he spent six years as an apprentice to a druggist in that town. In 1845 he went to London and entered Lyon Playfair's laboratory, subsequently working under R. W. Bunsen at Marburg. In 1847 he was appointed science-master at Queenwood school, Hampshire, where he first met J. Tyndall, and in 1851 first professor of chemistry at Owens College, Manchester. Returning to London six years later he became lecturer in chemistry at St Bartholomew's hospital, and in 1863 professor of chemistry at the Royal Institution. From an early age he engaged in original research with great success. Analytical problems, such as the isolation of certain organic radicals, attracted his attention to begin with, but he soon turned to synthetical studies, and he was only about twenty-five years of age when an investigation, doubtless suggested by the work of his master, Bunsen, on cacodyl, yielded the interesting discovery of the organo-metallic compounds. The theoretical deductions which he drew from the consideration of these bodies were even more interesting and important than the bodies themselves. Perceiving a molecular isonomy between them and the inorganic compounds of the metals from which they may be formed, he saw their true molecular type in the oxygen, sulphur or chlorine compounds of those metals, from which he held them to be derived by the substitution of an organic group for the oxygen, sulphur, &c. In this way they enabled him to overthrow the theory of conjugate compounds, and they further led him in 1852 to publish the conception that the atoms of each elementary substance have a definite saturation capacity, so that they can only combine with a certain limited number of the atoms of other elements. The theory of valency thus founded has dominated the subsequent development of chemical doctrine, and forms the groundwork upon which the fabric of modern structural chemistry reposes.