Henry Letheby
Henry Letheby (1816 – 28 March 1876) was an English
analytical chemist
and public health officer.
Early life
Letheby was born at
Society of Apothecaries) (1837) and PhD.[2]
Career
He was a lecturer on chemistry at the
Linnean Society and the Chemical Society. Letheby's chief work was the treatise On Food, Its Varieties, Chemical Composition, Nutriitive Value, Comparative Digestibility, Physiological Functions and Uses, Preparation, Culinary Treatment, Preservation, Adulteration &c., London, 1870. His official reports on the sanitary condition of London were published from time to time.[2]
Letheby designed an interrupter circuit for use with
back emf at its output each time it is switched. Early interrupters were operated by hand, but Golding Bird introduced an automatic interrupter which worked electromagnetically in 1838. The problem with Bird's interrupter, and the problem that Letheby wished to solve, was that the direction of flow of the electric current was in opposite directions during the make and the break operations. Medical applications of electricity often required a unidirectional current, particularly when treating nervous disorders. Letheby's design caused only either the make or the break current to flow to the patient by a mechanical arrangement of two spoked wheels. Letherby proposed that a further advantage of his machine was that the pulses from the make contact provided a rather lesser shock to the patient than the pulses from the break contact. This gave the physician some control in situation where large shocks were not needed.[3][4][5]
Personal life
In 1848 he married Elizabeth Carter (1825-1881) of Holloway.[6] He died on 28 March 1876 and is buried with Elizabeth on the east side of Highgate Cemetery.[citation needed]
Notes
- ^ doi:10.1093/ref:odnb/16520. (Subscription or UK public library membershiprequired.)
- ^ a b . Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.
- .
- ISBN 0-691-05952-7.
- ^ Henry Letheby, "A description of a new electro-magnetic machine adapted so as to give a succession of shocks in one direction", Medical Gazette, p. 858, 13 November 1846.
Summarised in The Retrospect of Practical Medicine and Surgery, no.15, pp. 81–82, January–July 1847. - ^ "Henry Letheby, England and Wales Marriage Registration Index, 1837-2005". www.familysearch.org. Retrieved 15 March 2021.
References
This article incorporates text from a publication now in the public domain: "Letheby, Henry". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.
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