MANSFIELD, CHARLES BLACHFORD

(b. Rowner, near Gosport, Hampshire, England, 8 May 1819; d. London, 26 February 1855),

aromatic organic reactions, chemistry, exploration, social reform.

The chemical and energy industries rely on processes for the separation of hydrocarbons. These were originally derived from coal tar, the by-product of the gas lighting and coke industries, and since the 1950s mainly from petroleum. In the late 1840s, Mansfield pioneered the separation of aromatic hydrocarbons such as benzene from coal tar, and from benzene he produced nitrobenzene, thus contributing to the later development of the synthetic dye industry. He was a social reformer, and also recorded the geography and resources of South America.

Charles Blachford Mansfield was born to the rector of Rowner when the latter was sixty years of age. His mother’s family were descendants of Edward IV, and owned Osborne House, on the Isle of Wight, though it was sold to Queen Victoria after a brother-in-law lost a fortune on gambling. The proceeds enabled Mansfield to lead an independent life, and to follow his interests in science, industry, and social issues. His strong Christian values led him to take up the cause of education and improved conditions for the working classes.

Mansfield was educated at private schools, first at Twyford, then at Winchester, where he was so badly treated by one master that he suffered a breakdown at the age of sixteen. On recovery, he had a private tutor in Northamptonshire, and came to the notice of the Marquess of Northampton, president of the Royal Society, who encouraged a strong interest in science and ornithology. In October 1839 Mansfield entered Clare Hall, Cambridge, but did not graduate with a BA until 1846. In 1847 he joined the Royal College of Chemistry, since 1845 directed by August Wilhelm Hofmann, who undertook research into coal-tar products. Mansfield, as assistant to Hofmann, isolated abundant supplies of the hydrocarbons benzene (then called benzole) and toluene (toluol) by distillation of coal-tar naphtha. Realizing the commercial potential, he drew up a 50,000-word patent, filed on 11 November 1847. Specified uses included conversion of benzene, through the action of nitric acid, into nitrobenzene, a compound that came into use as a synthetic perfume. Mansfield’s nitration allowed benzene and concentrated nitric acid to drop continuously from separate glass funnels into an upright coil of glass tubing, thereby preventing a great rise in the temperature. Other uses for benzene included illuminating gas, as described by Mansfield on 17 April 1849 before the Institute of Civil Engineers. He also proposed before the Royal Institution the use of benzene as a solvent. Benzene was later used extensively in dry cleaning. Mansfield had a good knowledge of metals and their salts, and in 1851–1852 lectured on metals before the Royal Institution. In his Theory of Salts, completed in 1855, he proposed a threefold system for classification of the elements that was not helped by an obscure system of nomenclature.

In January 1849 Mansfield went into business as a manufacturer in Hanover Square, not far from the Royal College of Chemistry. He assisted Read Holliday, a large tar distiller based in Huddersfield, to distill hydrocarbons, and promoted his “Gas or Air Light” illuminating machine. Mansfield resigned from the college in 1850. Hofmann was one of his customers, ordering nitrobenzene and its reduction product, aniline, for researches into aromatic bases. Mansfield also investigated a portable gas-producing unit, the enrichment of coal gas, and the manufacture of water gas. Following the discovery of the first synthetic, or aniline, dye by William Henry Perkin in 1856, the production of aromatic hydrocarbons and their nitro and amino compounds became essential to the synthesis of dyes, pharmaceuticals, explosives, and so on.

Mansfield’s colleagues included Thomas Hughes, the Reverend Frederick Denison Maurice, Francis Cranmer Penrose, and Nevil Story Maskelyne. His close friendship at Cambridge with the writer Charles Kingsley involved religion, magic, mesmerism, science, nature, and female company. Mansfield, a shy individual, was a vegetarian, teetotaler, and nonsmoker, and, according to Kingsley, extremely handsome, which led him into a series of complex romances. In 1842 he married Catherine Shafto, but they separated soon after; when she refused a divorce, he engaged in further affairs and studied at the medical school of St. George’s Hospital, London. Mansfield appears to have suffered from periods of mental instability and despair. This and his lifestyle no doubt explain why his graduation from Cambridge was delayed. In 1848, the year of revolutions, he cofounded, with John M. Ludlow and others, the Christian Socialist movement, visited Paris, and cared for the unwell Kingsley, another supporter of the Christian Socialists. Mansfield attempted to use a form of hypnosis called magnetizing to aid Kingsley.

Also in 1848, Mansfield participated in the establishment of what later became the South Paddington Working Men’s College. During the 1849 cholera epidemic in London he helped with the provision of clean water. His strong social concerns, and the description of a balloon machine made in Paris, no doubt inspired his 1850 article “Hints for Hygea,” published in the Tory Fraser’s Magazine. There, perhaps stimulated by Michael Faraday’s work on electricity, he took readers on a voyage by battery-powered hydrogen balloon to the utopian planet Hygea. Mansfield also prepared a description of steam-powered aerial navigation that was published posthumously.

In 1851 Mansfield proposed in the Christian Socialist that the Island of Sark be acquired for use as an experiment in socialism. In the same year he argued for a more equitable patent law. However, his Christian Scientist colleagues were unhappy with the revelation that he was keeping a mistress, though Mansfield countered that he was educating the lady and intended to marry her. That helped little, and the couple separated. In May 1852 Mansfield departed for South America, where in Brazil and Paraguay he wrote about the peoples, flora, fauna, and potential for British trade, and engaged in further romantic escapades. After his return to England in April 1853, Mansfield, at his home in Weybridge, Surrey, studied the fermentation of sugar, and carried on an affair with the wife of the writer George Meredith.

The success of Mansfield’s distillation process attracted imitators, and in 1854 even a claim of priority from the Manchester chemist Frederick Crace Calvert. For hazardous distillations Mansfield rented a small room beside the Regent’s Canal, close to St. John’s Wood, where in 1855 he prepared specimens of aromatic hydrocarbons for display at the Paris Exhibition. On 17 February his still, tended by an assistant, burst into flames. Mansfield and the assistant were severely burned while attempting to remove the still from the building. They were rushed to the hospital, where several days later both died. Hofmann visited Mansfield in the hospital just before his death, and was greeted with the refrain: “Here lie the ashes of Charles

B. Mansfield.”

BIBLIOGRAPHY

WORKS BY MANSFIELD

Benzole: Its Nature and Utility. London, 1849.

“Researches on Coal Tar.” Journal of the Chemical Society 1 (1849): 244–268.

“Hints for Hygea.” Fraser’s Magazine (1850).

Paraguay, Brazil and the Plate. Letters Written in 1852, 53.… With a Sketch of the Author’s Life by C. Kingsley. Cambridge, U.K.: Macmillan, 1856.

A Theory of Salts: A Treatise on the Constitution of Bipolar (TwoMembered) Chemical Compounds. Edited by Nevil Story Maskelyne. London, 1865.

Aerial Navigation. Edited by R. B. Mansfield, with a preface by J. M. Ludlow. London: Macmillan, 1877.

OTHER SOURCES

Travis, Anthony S. The Rainbow Makers: The Origins of the Synthetic Dyestuffs Industry in Western Europe. Bethlehem, PA: Lehigh University Press, 1993.

Ward, Edward R. “C. B. Mansfield v. F. Grace[sic] Calvert: A Forgotten Controversy in the Coal Tar Industry.” Chemistry and Industry (9 February 1957): 159–160.

_____. “Charles Blachford Mansfield 1819–1855: Coal Tar Chemist and Social Reformer.” Chemistry and Industry (25 October 1969): 1530–1537.

——. “Industrial Mixed Acid Nitration.” Ambix 23 (1976): 199–200.

_____. “Eminent Victorian: Charles Mansfield.” Chemistry in Britain 15 (1979): 297–304.

_____. “The Death of Charles Blachford Mansfield (1819–1855).” Ambix 31 (1984): 68–69.

Anthony S. Travis