SIR

See also:

• EDWARD

EDWARD

See also:

• SIR EDWARD FRANKLAND (1825-1899)

FRANKLAND (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 over-throw 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 . In applied chemistry Frankland's great work was in connexion with water-supply . Appointed a member of the second royal commission on the pollution of rivers in 1868, he was provided 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 A . W. 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 . His 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 he 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 in normal circumstances gives no light, 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 spectrum of an incandescent gas under increasing pressure, the sharp lines observable when it is extremely attenuated broadening out to nebulous bands as the pressure rises, till they merge in the continuous spectrum as the gas approaches a density comparable with that of the liquid state . An application of these results to solar physics in con-junction with Sir Norman Lockyer led to the view that at least the external layers of the sun cannot consist of matter in the liquid or solid forms, but must be composed of gases or vapours . Frankland and Lockyer were also the discoverers of helium . In 1868 they noticed in the solar spectrum a bright yellow line which did not correspond to any substance then known, and which they therefore attributed to the then hypothetical element, helium . Sir Edward Frankland, who was made a K.C.B. in 1897, died on the 9th of August 1899 while on a holiday at Golaa, Gudbrandsdalen, Norway . A memorial lecture delivered by Professor H . E . Armstrong before the London Chemical Society on the 31st of October 19oi contained many personal details of Frankland's life, together with a full discussion of his scientific work; and a volume of Autobiographical Sketches was printed for private circulation in 1902 . His original papers, down to 1877, were collected and published in that year as Experimental Researches in Pure, Applied and Physical Chemistry .