Henry James Slack
English journalist, activist and science writer
About Henry James Slack
Lived 1818 – 1896 (aged 77–78). Henry James Slack was a journalist and science journalist.
Henry James Slack (1818–1896) was an English journalist, activist and science writer.
Life The son of Joseph Slack, a cloth merchant, and Grace Slack, he was born in London on 23 October 1818, and educated at North End, Hampstead. He gave up a business career for journalism in 1846, and worked on the North Devon Journal and other provincial papers. He was elected a Fellow of the Geological Society in 1849.
In 1852, Slack became proprietor and editor of The Atlas, where Henry White was literary editor. He also wrote for the Weekly Times, under the signature "Little John".
Slack advocated liberal ideas: opposition to slavery, the abolition of the paper duties, and the higher education of women. He was a Cobdenite, and a member of the National Education League.
A friend of the politicians Lajos Kossuth and Giuseppe Mazzini, Slack spoke for Felice Orsini at Exeter Hall in 1856. He was closely identified with the Sunday League, was its president in 1879, and inaugurated the popular lectures for Sunday evenings. He also supported the Sunday opening of museums and picture-galleries, to promote which the Sunday Society was formed in 1875. He died at his home, Forest Row, Sussex, on 16 June 1896
Works Engraving from an 1867 paper of Henry James Slack, cells from a sample of red wine. In 1850, Slack published The Ministry of the Beautiful (London), a dialogue on aesthetics, and in 1860 an upbeat treatise The Philosophy of Progress in Human Affairs. The Marvels of Pond Life was a popular introduction to microscope studies (London, 1861; 3rd edit. illustrated, 1878), based on ponds that mostly were quite soon were built over. He was a regular contributor to Knowledge, and 46 papers under his name in the Royal Society's Scientific Catalogue were selected from Popular Science Monthly, the Meteorological Journal, and similar periodicals. In religion he was mainly influenced by the Unitarian William Johnson Fox, whose works he edited in a Memorial Edition (London, 12 vols. 1865–8), with William Ballantyne Hodgson. In 1868 he was introduced to William Michael Rossetti, as a "legal gentleman", leading to some opaque dealings with a role in literary history. Slack lent to Rossetti some letters of Percy Bysshe Shelley, which had been part of a correspondence in his early life with Elizabeth Hitchener. The story Slack told about how the letters had come into his possession was that he had had them from H. Holste, solicitor and executor to Hitchener who died aged 38 in 1821. What Slack told Thomas James Wise, who saw the letters through Rossetti, was that Hitchener had gone abroad, and married an Austrian officer. Rossetti was interested in publishing poems occurring in the letters, in particular To Mary who Died. Wise, however, unauthorised, published the letters. The letters had been deposited with Slack, on conditions that are unclear. It is also unclear why they were deposited, given that Slack was not a lawyer; and he did not claim he owned them; he gave an indication of the owner as a lady living in Germany.
The original letters passed from Slack's widow as a legacy to Charles Hargrove. From him they went to the British Museum in 1907, and so to the British Library.
Family Slacks's wife, Charlotte Mary Walters, whom he married in 1840, survived him.
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Important facts
People in Henry James Slack's life
Named in this biography and alive at the same time
Contemporaries
People whose lives overlapped Henry James Slack's
Frequently asked questions
Who was Henry James Slack?
English journalist, activist and science writer
When was Henry James Slack born?
Henry James Slack was born in 1818.
When did Henry James Slack die?
Henry James Slack died in 1896.
What was Henry James Slack's occupation?
Henry James Slack was a journalist and science journalist.
Sources & further reading
· Wikipedia: Henry James Slack
Cite this page
APA: Biography.guide. (2026). Henry James Slack. https://biography.guide/henry-james-slack/
MLA: "Henry James Slack." Biography.guide, https://biography.guide/henry-james-slack/.
Chicago: "Henry James Slack." Biography.guide. https://biography.guide/henry-james-slack/.
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