page_title: Edward Frankland
section_title: Scientific work
hierarchical_section_title: Edward Frankland / Scientific work
caption_attribution_description: English: RSC plaque, former County Court, Quay Street, Manchester
context_page_description: Sir Edward Frankland, KCB, FRS, FRSE was a British chemist. He was one of the originators of organometallic chemistry and introduced the concept of combining power or valence. An expert in water quality and analysis, he was a member of the second royal commission on the pollution of rivers, and studied London's water quality for decades. He also studied luminous flames and the effects of atmospheric pressure on dense ignited gas, and was one of the discoverers of helium.
context_section_description: From an early age, Frankland engaged in original research with great success. Analytical problems, such as the isolation of certain organic radicals, attracted his attention at first, but he soon turned to chemical syntheses. Robert Bunsen is believed to have directed his students, Edward Frankland and Hermann Kolbe, to the investigation of cacodyl, leading to Frankland's discovery of organometallic compounds. After his return to England Frankland achieved the synthesis of diethylzinc and dimethylzinc by the reaction of ethyl iodide and methyl iodide with metallic zinc.
  The theoretical deductions Frankland drew from considering 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, Frankland 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. Edward Frankland's 1852 publication on his discovery of the theory of valence was honoured by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society in 2015.
  In applied chemistry Frankland's great work was in connection with water-supply. Appointed a member of the second royal commission on the pollution of rivers in 1868, he was provided by the government with a completely equipped laboratory, in which, for a period of six years, he carried on the inquiries necessary for the purposes of that body, and was thus the means of bringing to light an enormous amount of valuable information respecting the contamination of rivers by sewage, trade-refuse, &c., and the purification of water for domestic use. In 1865, when he succeeded August Wilhelm von Hofmann at the School of Mines, he undertook the duty of making monthly reports to the registrar-general on the character of the water supplied to London, and these he continued down to the end of his life. At one time he was an unsparing critic of its quality, but in later years he became strongly convinced of its general excellence and wholesomeness.
  Frankland's analyses were both chemical and bacteriological, and his dissatisfaction with the processes in vogue for the former at the time of his appointment caused him to spend two years in devising new and more accurate methods. In 1859 Frankland passed a night on the very top of Mont Blanc in company with John Tyndall. One of the purposes of the expedition was to discover whether the rate of combustion of a candle varies with the density of the atmosphere in which it is burnt, a question which was answered in the negative. Other observations made by Frankland at the time formed the starting-point of a series of experiments which yielded far-reaching results. He noticed that at the summit the candle gave a very poor light, and was thereby led to investigate the effect produced on luminous flames by varying the pressure of the atmosphere in which they are burning. He found that pressure increases luminosity, so that hydrogen, for example, the flame of which gives no light in normal circumstances, burns with a luminous flame under a pressure of ten or twenty atmospheres, and the inference he drew was that the presence of solid particles is not the only factor that determines the light-giving power of a flame, Further, he showed that the spectrum of a dense ignited gas resembles that of an incandescent liquid or solid, and he traced a gradual change in the spectru
caption: A blue plaque erected Quay Street, Manchester
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