horse-chestnut, and in the majority of wind-pollinated plants.
Dichotomy (dī-kot´o-mi), a cutting in two; a division by pairs. Hence, in botany, a mode of branching by constant forking, each branch dividing into two others. See Branching.
Dichroic, or more generally Pleochroic, Crystals (dī-krō´ik), crystals that have the property of exhibiting different colours, according to the direction in which they are traversed by rays of light. When polarized light is passed through a transparent plate of a pleochroic mineral, the colour will vary with the direction in which the light-vibrations take place. Hence, face-pleochroism, the colour of the plate, may be distinguished from the colours given by axis-pleochroism, the colours given by light vibrating parallel with certain optical directions in the crystal.
Dichroite (dī´kro-īt), or Iolite, a mineral, a silicate of magnesium, iron, and aluminium, which readily undergoes modifications and passes into hydrous silicate. It exhibits marked pleochroism, whence the name.
Dick, Thomas, LL.D., a Scottish author of popular scientific works, born at Dundee in 1774, died 29th July, 1857. He was for many years a teacher at Perth, but subsequently resided at Broughty-Ferry, where he devoted himself to astronomical science, especially in its relations to religion. Some years before his death a small pension was granted to him by the Government. Amongst his works are: The Christian Philosopher (1823), The Philosophy of Religion (1825), The Philosophy of a Future State (1828), and Celestial Scenery (1838).
Dickens, Charles, one of the greatest English novelists, born 7th Feb., 1812, at Landport, Portsmouth, died 9th June, 1870. His father, John Dickens, was then in the employment of the Navy Pay Department, but subsequently became a newspaper reporter in London. Young Dickens received a somewhat scanty education, was for a time a mere drudge in a blacking warehouse, and subsequently a clerk in an attorney's office. Having perfected himself in shorthand, however, he became a newspaper critic and reporter, was engaged on The Mirror of Parliament, and The True Sun, and in 1835 on The Morning Chronicle. For some time previously he had been contributing humorous pieces to The Monthly Magazine; but at length, in 1835, appeared in The Morning Chronicle the first of that series of Sketches by Boz which brought Dickens into fame. It was followed in quick succession by a pamphlet entitled Sunday under Three Heads, by Timothy Spark (1836); The Tuggs at Ramsgate (1836); The Village Coquette, a comic opera (1836); and a farce called The Strange Gentleman (1836). In the same year Chapman & Hall engaged the new writer to prepare the letterpress for a series of comic sketches on sporting subjects by Seymour, an artist who had already achieved fame, and suggested as a subject the adventures of an eccentric club. Seymour committed suicide soon after, and H. K. Browne joined Dickens as illustrator, the result being the immortal Pickwick Papers. The great characteristics of Dickens's genius were now fully apparent, and his fame rose at once to the highest point it was possible for a writer of fiction to reach. A new class of characters, eccentric indeed, but vital representations of the humours and oddities of life, such as Mr. Pickwick, Sam Weller and his father, Mr. Winkle, and others, was made familiar to the public. Under the name of The Posthumous Papers of the Pickwick Club this work was published in 2 vols. 8vo, in 1837. In the same year Dickens was engaged as editor of Bentley's Magazine, to which he contributed Oliver Twist, a work which opened up that vein of philanthropic pathos and indignant satire upon institutions which became a distinguishing feature of his works. Before the completion of Oliver Twist, Nicholas Nickleby was begun, being issued complete in 1839. As the special object of Oliver Twist was to expose the conduct of workhouses, that of Nicholas Nickleby was to denounce the management of cheap boarding-schools. Master Humphrey's Clock, issued in weekly numbers, contained among other matter two other leading tales, The Old Curiosity Shop and Barnaby Rudge, the latter a historical tale, going back to the times of the Gordon riots. It was published complete between 1840 and 1841. In 1841 Dickens visited America, and on his return he wrote American Notes for General Circulation (1842). His next novel, Martin Chuzzlewit (1844), dwelt again on his American experiences. This work also added a number of typical figures—Mr. Pecksniff, Mark Tapley, Sarah Gamp, and others—to English literature. The series of Christmas Tales, in which a new element of his genius, the power of handling the weird machinery of ghostly legend in subordination to his own peculiar humour, excited a new sensation of wonder and delight. These, enumerated consecutively, were: A Christmas Carol (1843), The Chimes (1844), The Cricket on the Hearth (1845), The Battle of Life (1846), The Haunted Man and The Ghost's Bargain (1847). The extraordinary popularity of these tales created for a time a new department in literature, that of the sensational tale for the Christmas season. In 1845 Dickens went to Italy, and on his return The Daily News, started on 1st Jan., 1846, was entrusted to his editorial management; but, despite his early training, this was an
occupation uncongenial to his mind, and in a few months the experiment was abandoned. His Pictures from Italy were published the same year. Next followed his novel of Dombey and Son (1848), and David Copperfield, a work which has a strong autobiographical element in it (1849-50). In 1850 Dickens became editor of the weekly serial Household Words, in which various original contributions from his own pen appeared. In 1853 his Bleak House came out. A Child's History of England, commenced in Household Words, was published between 1852 and 1854. Hard Times appeared in Household Words, and was published in 1854. Little Dorrit, commenced in 1856, dealt with imprisonment for debt, the contrasts of character developed by wealth and poverty, and executive imbecility, idealized in the Circumlocution Office. In 1859, in consequence of a disagreement with his publishers, All the Year Round superseded Household Words; and in the first number of this periodical, 28th May, was begun A Tale of Two Cities. Great Expectations followed in the same paper, on 1st Dec., 1860. In All the Year Round also appeared a series of disconnected sketches called The Uncommercial Traveller, published in 1868. Our Mutual Friend, completed in 1865, and published in the usual monthly numbers, with illustrations by Marcus Stone, was the last great serial work which Dickens lived to finish. It contained some studies of characters of a breadth and depth unusual with Dickens, and is distinguished among his works by its elaborate plot. The first number of his last work, The Mystery of Edwin Drood, was issued on 1st April, 1870, and only three numbers had appeared when he died somewhat suddenly, at his residence, Gad's Hill Place, near Rochester, on 9th June. He had considerably overtaxed his strength during his later years, more especially by his successive series of public readings from his own works, one series being delivered in America between 1867 and 1868. He was buried in Westminster Abbey. Dickens's work as a novelist is firmly based upon a wide and keen observation of men. The essence of his art was caricature, and for comic effect he, therefore, often exaggerated the abuses he attacked. His characters exhibit little more than one trait or quality, but the single trait or quality which they embody is truly conceived, and exhibited with great vitality and humour. His creative power was immense, and his great humour is admitted by all, even by those who consider his pathos as overdrawn. In spite, therefore, of all that is grotesque and overstrained in his work, he has been rightly placed amongst the great artists.—Bibliography: J. Forster, Life of Charles Dickens; George Gissing, Charles Dickens: a Critical Study; G. K. Chesterton, Charles Dickens; R. H. Shepherd, The Bibliography of Dickens; Sir F. T. Marzials, Life of Charles Dickens; E. Pugh, The Charles Dickens Originals; P. H. Fitzgerald, Memoirs of Charles Dickens.
Dicksonia, a genus of Leptosporangiate ferns, section Gradatæ, mostly large tree-ferns, such as D. antarctica, a native of Australia and New Zealand, often grown in greenhouses.
B, Bast. B.K., Bark external to the first periderm layer, corresponding to the primary cortex. C, Cambium ring. E, Early wood. J, J, J, Junction of the wood of successive years. L, Late wood. M, Medulla. M.R., Medullary rays, various views. P, Protoxylem. 1, 2, 3, 4, The four successive annual rings.